| Tsuyoshi Yoshitake | Last modified date：2023.07.07 |
Professor /
Applied Electromagnetics /
Department of Advanced Energy Science and Engineering /
Faculty of Engineering Sciences
Papers
| 1. | Sreenath Mylo Valappil, Abdelrahman Zkria, Shinya Ohmagari, Tsuyoshi Yoshitake, Overcoming the impact of post-annealing on uniformity of diamond (100) Schottky barrier diodes through corrosion-resistant nanocarbon ohmic contacts, Materials Research Express, https://doi.org/10.1088/2053-1591/aca31f, Volume 9, Number 11 (2022) 115901, 2023.07. |
| 2. | Phongsaphak Sittimart, Shinya Ohmagari, Hitoshi Umezawa, Hiromitsu Kato, Kotaro Ishiji, Tsuyoshi Yoshitake, Thermally Stable and Radiation-Proof Visible-Light Photodetectors Made from N-Doped Diamond, Advanced Optical Materials , https://doi.org/10.1002/adom.202203006, Volume11, Issue12, June 19, 2023, 2203006, 2023.07. |
| 3. | Mohamed Egiza, Ali M. Ali, Koki Murasawa, and Tsuyoshi Yoshitake, B-doped nanodiamond composite hard coatings deposited on cemented carbide: Mechanical, structural, and tribological properties, International Journal of Refractory Metals and Hard Materials, https://doi.org/10.1016/j.ijrmhm.2023.106260, Volume 114, August 2023, 106260, 2023.07. |
| 4. | Mohammed Rabie, Asmaa Elrasheedy, Abdelrahman Zkria, M.F. Elkady, Tsuyoshi Yoshitake, A.H. El-Shazly, Hybrid concentrator photovoltaic/membrane distillation system for potable water production using new fabricated PS/ZIF_L membrane, Journal of Water Process Engineering, Volume 53, July 2023, 103872, 2023.07. |
| 5. | Mohammed Rabie, M.F. Elkady, Tsuyoshi Yoshitake, A.H. El-Shazly, Hybridized high concentration photovoltaic unit with enhanced performance air gap membrane distillation unit via depositing reduced graphene oxide layer upon the condensation plate using electrophoretic deposition technique, Energy Reports, https://doi.org/10.1016/j.egyr.2022.10.384, Volume 9, Supplement 1, March 2023, Pages 230-238, 2023.03. |
| 6. | Sreenath Mylo Valappil, Abdelrahman Zkria, Shinya Ohmagari, Hiroshi Naragino, Hiromitsu Kato, Tsuyoshi Yoshitake, Corrosion-resistive and Low Specific Contact Resistance Ohmic Contacts to Semiconducting Diamonds Using Nanocarbon electrodes, Phys. Status Solidi A, https://doi.org/10.1002/pssa.202200627, Volume220, Issue3 (2023) 2200627, 2023.02. |
| 7. | Lama Osman, Ali M. Ali, Abdelrahman Zkria, Hiroshi Naragino, Tsuyoshi Yoshitake, Adhesion of Nanodiamond composite films on Ti substrates at Room Temperature via hybrid ion etching gun and coaxial arc plasma deposition, Applied Physics Express, https://iopscience.iop.org/article/10.35848/1882-0786/ac99b6, Vol. 15, Number 11 (2022) 115004, 2022.10. |
| 8. | Peerasil Charoenyuenyao, Rawiwan Chaleawpong, Nattakorn Borwornpornmetee, Boonchoat Paosawatyanyong, Phongsaphak Sittimart, Tsuyoshi Yoshitake, and Nathaporn Promros, Investigation of morphological surface features, wetting behavior and mechanical traits under various substrate temperatures for beta iron disilicide prepared via facing-targets sputtering, Materials Science in Semiconductor Processing , https://doi.org/10.1016/j.mssp.2022.106604, Vol. 146 (2022) 106604, 2022.08. |
| 9. | Nattakorn Borwornpornmetee, Rawiwan Chaleawpong, Peerasil Charoenyuenyao, Adison Nopparuchikun, Boonchoat Paosawatyanyong, Phongsaphak Sittimart, Tsuyoshi Yoshitake, and Nathaporn Promros, Reverse bias dependent impedance and dielectric properties of Al/n-NC FeSi2/p-Si/Pd heterostructures formed by facing-targets sputtering, Materials Science in Semiconductor Processing, https://doi.org/10.1016/j.mssp.2022.106641, Vol. 146 (2022) 106641, 2022.08. |
| 10. | Sreenath Mylo Valappil, Shinya Ohmagari, Abdelrahman Zkria, Phongsaphak Sittimart, Eslam Abubakr, Hiromitsu Kato, Tsuyoshi Yoshitake, Nanocarbon electrodes fabricated by coaxial arc plasma deposition for phosphorus-doped diamond electronics application, AIP Advances , https://doi.org/10.1063/5.0093470, 12, 085007 (2022), 2022.08. |
| 11. | Nattakorn Borwornpornmetee, Peerasil Charoenyuenyao, Rawiwan Chaleawpong, Boonchoat Paosawatyanyong, Rungrueang Phatthanakun, Phongsaphak Sittimart, Kazuki Aramaki, Takeru Hamasaki, Tsuyoshi Yoshitake, and Nathaporn Promros, Physical Properties of Fe3Si Films Coated through Facing Targets Sputtering after Microwave Plasma Treatment, Coating, https://doi.org/10.3390/coatings11080923, Vol. 11 (2021) 923, 2022.06. |
| 12. | Eslam Abubakr, Shinya Ohmagari, Abdelrahman Zkria, Hiroshi Ikenoue, Julien Pernot, and Tsuyoshi Yoshitake, Formation of p-n+ diamond homojunctions by shallow doping of phosphorus through liquid emersion excimer laser irradiation, Materials Research Letters, https://doi.org/10.1080/21663831.2022.2083457, Vol. 10, Issue 10 (2022) pp. 666-674, 2022.06. |
| 13. | Eslam Abubakr, Shinya Ohmagari, Abdelrahman Zkria, Hiroshi Ikenoue, Julien Pernot, Tsuyoshi Yoshitake, Formation of p-n+ diamond homojunctions by shallow doping of phosphorus through liquid emersion excimer laser irradiation, Materials Research Letters, https://doi.org/10.1080/21663831.2022.2083457, Vol. 10, Issue 10 (2022) pp. 666-674, 2022.06. |
| 14. | Asmaa Elrasheedy, Marwa El Kady, Mohamed Bassyouni, Tsuyoshi Yoshitake, Ahmed Elshazly, Enhancement of Antiwetting Properties of Polystyrene Nanofibrous Membrane by Doping with Graphene Nanoplatelets, Materials Science Forum, https://doi.org/10.4028/p-suy72p, Vol. 1060 (2023) pp. 83-88, 2022.05. |
| 15. | Tomoki Iwao, Phongsaphak Sittimart, Tsuyoshi Yoshitake, Hitoshi Umezawa, Shinya Ohmagari, Impact of Laser-Induced Graphitization on Diamond Schottky Barrier Diodes, physica status solidi (a) , https://doi.org/10.1002/pssa.202100846, (2022) 2100846, 2022.04. |
| 16. | Eslam Abubak, ShinyaOhmagar, Abdelrahman Zkria, Hiroshi Ikenoue, and Tsuyoshi Yoshitake, Laser-induced novel ohmic contact formation for effective charge collection in diamond detectors, Materials Science in Semiconductor Processing, https://doi.org/10.1016/j.mssp.2021.106370, Vol. 139 (2022) 106370, 2022.03, In this study, we employed an authentic process for the device fabrication of diamond detectors, wherein thin, highly conductive surface layers were processed in bulk diamond substrate using a nanosecond-pulsed excimer laser with liquid-immersion irradiation. The incorporation of high-concentration phosphorus dopants at 40 nm under the irradiated surface characterized the irradiated areas with much lower electrical resistivity, which was adequate for demonstrating ohmic contacts even with the tungsten probe heads at room temperature. In particular, a low activation energy ( |
| 17. | Abdelrahman Zkria, Ali M. Ali, Imtenan Mahmoud, Abdalla Abdelwahab, Waleed M. A. El Rouby, and Tsuyoshi Yoshitake, Nanodiamond/Conducting Polymer Nanocomposites for Supercapacitor Applications, Book chapter in “Advances in Nanocomposite Materials for Environmental and Energy Harvesting Applications” (Springer, 2022) , https://doi.org/10.1007/978-3-030-94319-6_32, pp. 1017-1045, 2022.03. |
| 18. | Abdelrahman Zkria, Hiroki Gima, Eslam Abubakr, Ashraf Mahmoud, Ariful Haque, and Tsuyoshi Yoshitake, Correlated Electrical Conductivities to Chemical Configurations of Nitrogenated Nanocrystalline Diamond Films, Nanomaterials , https://doi.org/10.3390/nano12050854, Vol. 12 (2022) 854, 2022.03. |
| 19. | Joshua Anani, Hussien Noby, Abdelrahman Zkria, Tsuyoshi Yoshitake, and Marwa ElKady, Monothetic analysis and response surface methodology optimization of calcium alginate microcapsules characteristics, Polymers , https://doi.org/10.3390/polym14040709, Vol. 14 (2022) 709, 2022.02. |
| 20. | Eslam Abubakr，Hiroshi Ikenoue，Tsuyoshi Yoshitake, Highly Conductive Layers Formation on Singlecrystalline Diamond, NEW DIAMOND, 第143号，Vol. 37、No. 4 (2021) pp.16-17, 2021.11. |
| 21. | Phongsaphak Sittimart, Shinya Ohmagari, Takashi Matsumae, Hitoshi Umezawa, and Tsuyoshi Yoshitake, Diamond/β-Ga2O3 pn heterojunction diodes fabricated by low-temperature direct-bonding, AIP Advances, https://doi.org/10.1063/5.0062531, Vol. 11 (2021) 105114, 2021.10. |
| 22. | Ali M. Ali, Mohamed Egiza, Koki Murasawa, Hiroaki Sugita, Tanja Deckert-Gaudig, Volker Deckert, Tsuyoshi Yoshitake, Effects of substrate temperature and intermediate layer on adhesion, structural and mechanical properties of coaxial arc plasma deposition grown nanodiamond composite films on Si substrates , Surface & Coatings Technology, https://doi.org/10.1016/j.surfcoat.2021.127185, Vol. 417, 127185, 2021.06, Low-temperature fabrication of nanodiamond films on untreated silicon substrates, which are preferred sub-strates and widely employed in industry, can extend nanodiamond film applications, for instance in biosensing and miniaturization technologies. For its realization, the weak adhesion of nanodiamond films on silicon sub-strates due to insufficient atomic interdiffusion at the interfaces is a serious issue that needs to be overcome. In the present study, coaxial arc plasma deposition (CAPD) grown nanodiamond films were fabricated at low temperatures on silicon substrates. The effects of the substrate temperature, which is an important parameter in the CAPD nanodiamond film growth process, were structurally and physically investigated. It was found that the films softened with increasing substrate temperature and atomic interdiffusions at interfaces between the films and substrates were activated, which resulted in the formation of SiC at the interfaces. On the other hand, the films fabricated directly on silicon at room temperature were exfoliated due to the poor adhesion and high re-sidual stress. Consequently, intermediate layers that were fabricated at elevated substrate temperatures were employed to improve the adhesion strength of nanodiamond films on silicon substrates. This way, the atomic interdiffusion at the interfaces could be promoted and the residual stress in the films was relieved. In the second stage, the films were fabricated on the intermediate layers at different temperatures. It has shown that the top layer films fabricated at low temperature gained distinctive mechanical and structural properties. By applying this strategy, several micrometres of hard nanodiamond films can be fabricated on Si substrates without easily being peeled off.. |
| 23. | Phongsaphak Sittimart, Shinya Ohmagari, Tsuyoshi Yoshitake, Enhanced in-plane uniformity and breakdown strength of diamond Schottky barrier diodes fabricated on heteroepitaxial substrates, Jpn. J. Appl. Phys., https://iopscience.iop.org/article/10.35848/1347-4065/abd537, Vol. 60, SBBD05, 2021.01. |
| 24. | Eslam Abubakr, Abdelrahman Zkria, Shinya Ohmagari, Yu̅ki Katamune, Hiroshi Ikenoue, Tsuyoshi Yoshitake, Laser-Induced Phosphorus-Doped Conductive Layer Formation on Single-crystal Diamond Surfaces, ACS Applied Materials & Interfaces, DOI: 10.1021/acsami.0c18435, 12, pp. 57619-57626, 2020.12, A laser-induced doping method was employed to incorporate phosphorus into an insulating monocrystalline diamond at ambient temperature and pressure conditions. Pulsed laser beams with nanosecond duration (20 ns) were irradiated on the diamond substrate immersed in a phosphoric acid liquid, in turns, and a thin conductive layer was formed on its surface. Phosphorus incorporation in the depth range of 40−50 nm below the irradiated surface was confirmed by secondary ion mass spectroscopy (SIMS). Electrically, the irradiated areas exhibited ohmic contacts even with tungsten prober heads at room temperature, where the electrical resistivity of irradiated areas was greatly decreased compared to the original surface. The temperature dependence of the electrical conductivity implies that the surface layer is semiconducting with activation energies ranging between 0.2 eV and 54 meV depending on irradiation conditions. Since after laser treatment no carbon or graphitic phases other than diamond is found (the D and G Raman peaks are barely observed), the incorporation of phosphorus is the main origin of the enhanced conductivity. It was demonstrated that the proposed technique is applicable to diamond as a new ex situ doping method for introducing impurities into a solid in a precise and well-controlled manner, especially with electronic technology targeting of smaller devices and shallower junctions.. |
| 25. | Mahmoud SHABAN, Abdelrahman ZKRIA, Tsuyoshi YOSHITAKE, Temperature-Dependent Impedance Spectra of Nitrogen-Doped Ultrananocrystalline Diamond Films Grown on Si Substrates, IEEE Access, DOI: 10.1109/ACCESS.2020.3046969, 2020.11. |
| 26. | Zkria Abdelrahman, Mahmoud Shaban, Abubakr Eslam, Tsuyoshi Yoshitake, Impedance spectroscopy analysis of n-type (nitrogen-doped) ultrananocrystalline diamond/p-type Si heterojunction diodes, Physica Scripta, https://doi.org/10.1088/1402-4896/aba97e, 95, 9, 095803, 2020.09. |
| 27. | Rawiwan Chaleawpong, Nathaporn Promros, Abdelrahman Zkria, Peerasil Charoenyuenyao, Eslam Abubakr, Tsuyoshi Yoshitake, Diode parameters and ultraviolet light detection characteristics of n-type silicon/p-type nanocrystalline diamond heterojunctions at different temperatures, Thin Solid Films, https://doi.org/10.1016/j.tsf.2020.138229, Vol. 709, (2020) 138229, 2020.07. |
| 28. | Peerasil Charoenyuenyao, Nathaporn Promros, Rawiwan Chaleawpong, Nattakorn Borwornpornmetee, Pattarapol Sittisart, Yūki Tanaka, Tsuyoshi Yoshitake, Impact of Annealing Temperature and Carbon Doping on the Wetting and Surface Morphology of Semiconducting Iron Disilicide Formed via Radio Frequency Magnetron Sputtering, Thin Solid Films, https://doi.org/10.1016/j.tsf.2020.138248, Vol. 709 (2020) 138248, 2020.07. |
| 29. | Ali M. Ali, Mohamed Egiza, Koki Murasawa, Hiroaki Sugita, Tanja Deckert-Gaudig, Volker Deckert, and Tsuyoshi Yoshitake, Influence of adhesion intermediate layers on the stability of nanodiamond composite films deposited on Si substrates by coaxial arc plasma, Applied Physics Express, https://doi.org/10.35848/1882-0786/ab91d1, Vol. 13, No. 6 (2020) 065506, 2020.06, Raman spectroscopic studies on nanodiamond composite (NDC) films, comprising nano-sized diamond grains and an amorphous carbon (a-C) matrix, deposited by coaxial arc plasma deposition are challenging because the scattering of the nano-sized diamond grains competes with the strong signal of the a-C matrix. To unravel the nanocomposite structure of NDC films, both far- and near-field Raman spectroscopy were employed. Based on the comparison of visible and ultraviolet far-field Raman data, component spectra based on either nanodiamond or a-C were estimated by a peak-decomposition procedure based on band fitting. Near-field optical resolution achieved via tip-enhanced Raman spectroscopy reveals sharper peaks of both the nanodiamond and the amorphous carbon than the far-field spectra. Consequently, the peak-decomposition procedure is not required, which evidently indicates the effective detection of nanodiamond grains embedded in a-C matrices and is a direct result of the high spatial resolution that limits the number of probed grains. The size of the nanocrystals could additionally be estimated from the profile and position of a diamond peak. This work demonstrates that tip-enhanced Raman spectroscopy is a powerful nondestructive method for nanodiamond composite films, which allows direct access to parameters hitherto only available via average data.. |
| 30. | Abdelrahamn Zkria, Eslam Abubakr, Phongsaphak Sittimartt, Tsuyoshi Yoshitake , Analysis of electrical characteristics of Pd/n-nanocarbon/p-Si heterojunction diodes: by C-V-f and G/w-V-f, Journal of Nanomaterials, https://doi.org/10.1155/2020/4917946, 2020, Article ID 4917946, 9 pages, 2020.06. |
| 31. | Takuya Sakai, Takeru Hamasaki, Kazuki Kudo, Ken-ichiro Sakai, Hiroyuki Deguchi, Tsuyoshi Yoshitake, Spin-Valve Effects in Fe/N-Doped Carbon/Fe3Si Trilayered Films, JJAP Conf. Proc., https://doi.org/10.7567/JJAPCP.8.011202, Vol. 8, 011202, 2020.06. |
| 32. | Abdelrahman Zkria, Mohamed Egiza, Ariful Haque, Eslam Abubakr, Jagdish Narayan, Tsuyoshi Yoshitake, Monitoring laser-induced structural evolution of hydrogenated nanodiamond composite films prepared by coaxial arc plasma deposition, Applied Physics Express, https://iopscience.iop.org/article/10.35848/1882-0786/abb871, Vol. 13, No. 10, 105503, 2020.06. |
| 33. | Takeshi Hara, Hiroki Hashiguchi, Masumi Ogishima, Daisuke Fujimoto, Tsuyoshi Yoshitake, Electrochemical detection characteristics of the composite films of boron-doped nanocrystalline diamond and amorphous carbon prepared using the coaxial arc plasma deposition method, IEEJ Transactions on Electrical and Electronic Engineering, 10.1002/tee.23157, 2020.01, In this study, we applied coaxial arc plasma deposition in vacuum and without substrate heating to prepare composite films of boron-doped nanocrystalline diamond and amorphous carbon (B-doped NCD/a-C) exhibiting electrochemical characteristics similar to those exhibited by the conductive polycrystalline diamond electrodes. Furthermore, we confirmed that the deposited films can be used to determine the current density owing to various concentrations of potassium ferricyanide (K3[Fe(CN6)]). Moreover, the concentration of K3[Fe(CN6)] and its current density were strongly correlated. Based on these experimental results, the deposited films were highly valuable as electrodes for electrochemical sensors.. |
| 34. | M. Ali Ali, Tanja Deckert-Gaudig, Mohamed Egiza, Volker Deckert, Tsuyoshi Yoshitake, Near- And far-field Raman spectroscopic studies of nanodiamond composite films deposited by coaxial arc plasma, Applied Physics Letters, 10.1063/1.5142198, 116, 4, 2020.01, Raman spectroscopic studies on nanodiamond composite (NDC) films, comprising nano-sized diamond grains and an amorphous carbon (a-C) matrix, deposited by coaxial arc plasma deposition are challenging because the scattering of the nano-sized diamond grains competes with the strong signal of the a-C matrix. To unravel the nanocomposite structure of NDC films, both far- and near-field Raman spectroscopy were employed. Based on the comparison of visible and ultraviolet far-field Raman data, component spectra based on either nanodiamond or a-C were estimated by a peak-decomposition procedure based on band fitting. Near-field optical resolution achieved via tip-enhanced Raman spectroscopy reveals sharper peaks of both the nanodiamond and the amorphous carbon than the far-field spectra. Consequently, the peak-decomposition procedure is not required, which evidently indicates the effective detection of nanodiamond grains embedded in a-C matrices and is a direct result of the high spatial resolution that limits the number of probed grains. The size of the nanocrystals could additionally be estimated from the profile and position of a diamond peak. This work demonstrates that tip-enhanced Raman spectroscopy is a powerful nondestructive method for nanodiamond composite films, which allows direct access to parameters hitherto only available via average data.. |
| 35. | Takeshi Hara, Masaya Onishi, Takumi Takenaga, Yuta Inoue, Masumi Ogishima, Daisuke Fujimoto, and Tsuyoshi Yoshitake, Characteristics of electrochemical electrodes containing composite films of boron-doped nanocrystalline diamond and amorphous carbon, Journal of Institute of Industrial Applications Engineers, DOI: 10.12792/JIIAE.7.99, 7, 3, 99-105, 2019.08. |
| 36. | Mohamed Egiza, Kouki Murasawa, Ali M. Ali, Yasuo Fukui, Hidenobu Gonda, and Masatoshi Sakurai, and Tsuyoshi Yoshitake, Enhanced hardness of nanocarbon films deposited on cemented tungsten carbide substrates by coaxial arc plasma deposition owing to employing silicon-doped graphite targets, Japanese Journal of Applied Physics, https://iopscience.iop.org/article/10.7567/1347-4065/ab289f, 58, 7, 075507. , 2019.07, . |
| 37. | Abdelrahman Zkria, Ariful Haque, Mohamed Egiza, Eslam Abubakr, Koki Murasawa, Tsuyoshi Yoshitake, Jagdish Narayan, Laser-induced structure transition of diamond-like carbon coated on cemented carbide and formation of reduced graphene oxide, MRS Communications, DOI: https://doi.org/10.1557/mrc.2019.88, 1-6, 2019.07. |
| 38. | Ali M. Ali, Mohamed Egiza, Koki Murasawa, Yasuo Fukui, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Negative bias effects on deposition and mechanical properties of ultrananocrystalline diamond/amorphous carbon composite films deposited on cemented carbide substrates by coaxial arc plasma, Diamond and Related Materials, 10.1016/j.diamond.2019.04.031, 96, 67-73, 2019.06, Ultrananocrystalline diamond/amorphous carbon composite (UNCD/a-C) films were deposited on negatively biased cemented carbide (WC-Co) substrates by coaxial arc plasma deposition. The deposition rate is increased to be 0.9 nm/s, which is approximately 3 times larger than that of films deposited under no bias condition. In addition, the critical load in scratch tests was enhanced to be 31 N, which is 4 times more than that of the no bias films. On the other hand, the hardness was slightly degraded by employing the negative bias. From electrical diagnostics of the bias application, it was found that the negative bias is immediately compensated by the arrival of highly-dense positive carbon ions at the substrate and the substrate is weakly positively charged after the compensation. This might be the main reason for the degraded hardness by the bias application, Since the positive bias deaccelerate carbon ions, which facilities the formation of sp2 bonds.. |
| 39. | Yūki Katamune, Satoshi Takeichi, Ryota Ohtani, Satoshi Koizumi, Eiji Ikenaga, Kazutaka Kamitani, Takeharu Sugiyama, Tsuyoshi Yoshitake, Electrical properties of boron-incorporated ultrananocrystalline diamond/hydrogenated amorphous carbon composite films, Applied Physics A: Materials Science and Processing, 10.1007/s00339-019-2607-8, 125, 5, 2019.05, Boron-incorporated ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited by coaxial arc plasma deposition with boron-blended graphite targets. The effects of boron incorporation on the electrical properties of the films were investigated by hard X-ray photoelectron spectroscopy. Their electrical conductivity increased from 10−7 to 10−1 Ω−1 cm−1 with increasing boron content up to 5 at.%. From the temperature dependence of electrical conductivity, hopping conduction due to localized states produced by boron atoms is predominant in carrier transport. X-ray photoelectron spectra showed the shifts of Fermi levels toward the top of the valence band with increasing boron content. It implies that boron atoms in the films lead to form localized states, which results in enhanced electrical conductivity.. |
| 40. | Eslam Abubakr, Abdelrahman Zkria, Yūki Katamune, Shinya Ohmagari, Kaname Imokawa, Hiroshi Ikenoue, Tsuyoshi Yoshitake, Formation of low resistivity layers on singlecrystalline diamond by excimer laser irradiation, Diamond and Related Materials, 10.1016/j.diamond.2019.04.013, 95, 166-173, 2019.05, A singlecrystalline diamond (100)(Ib) plate immersed in 2% boric acid was irradiated by 193-nm ArF excimer laser beams for the formation of conductive layers on the surface of an insulating diamond substrate. From current-voltage measurements of the irradiated areas, it was confirmed that semiconducting layers with high conductivities are formed on the diamond surface. It was possible to form ohmic contacts by directly touching tungsten probes with the layer surface. Since Raman spectra exhibited only peaks due to diamond and no peaks due to amorphous carbon, the drastically enhanced conductivity is not attributed to amorphous carbon formation but due to the incorporation of boron atoms into the diamond subsurface from the dopant acid. Secondary ion mass spectrometric depth profile showed the incorporation of boron atoms up to 40 nm depths from the surface. From cathodoluminescence measurements at low temperatures, it was difficult to detect clear peaks for the substitutional incorporation of boron atoms into diamond lattices, which could be attributed to the small thickness of the doped layer for detection. The proposed technique is a new potential method for shallow doping and formation of conductive layers on singlecrystalline diamond surfaces.. |
| 41. | Rawiwan Chaleawpong, Nathaporn Promros, Peerasil Charoenyuenyao, Takanori Hanada, Shinya Ohmagari, Abdelrahman Zkria, Tsuyoshi Yoshitake, Diode Parameters of Heterojunctions Comprising p-Type Ultrananocrystalline Diamond Films and n-Type Si Substrates, Journal of Nanoscience and Nanotechnology, 10.1166/jnn.2019.16232, 19, 3, 1567-1573, 2019.03, In the current research, heterojunctions comprising p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films and n-type Si substrates were formed via pulsed laser deposition. To extract their junction parameters via thermionic emission (TE) theory and Norde model, the measurement of dark current density-voltage curves was carried out under various temperatures ranging from 300 to 60 K. Through TE theory, the ideality factor values at 300 K and 60 K were 2.70 and 8.66, respectively. This justified that a heavy recombination process occurs at the junction interface in addition to another tunneling process at 300 K. The tunneling process is predominant at low temperatures. The barrier height values were 0.78 eV and 0.18 eV at 300 K and 60 K, respectively. The values for series resistance (Rs) calculated via Norde model at 300 K and 60 K were 275.24 Ω and 78.66 kΩ, respectively. The increment of Rs at low temperatures was likely due to the decrease of carrier concentration in the B-doped UNCD/a-C:H films when temperature was decreased.. |
| 42. | Rawiwan Chaleawpong, Nathaporn Promros, Peerasil Charoenyuenyao, Takanori Hanada, Shinya Ohmagari, and Tsuyoshi Yoshitake, Temperature Dependence of Alternating Current Impedance in n-Type Si/B-doped p-Type Ultrananocrystalline Diamond Heterojunctions Produced through Pulsed Laser Deposition, Journal of Nanoscience and Nanotechnology, https://doi.org/10.1166/jnn.2019.16232, 19, 3, 1567-1573, 2019.03, . |
| 43. | Abdelrahman Zkria, Fouad Abdel-Wahab, Yuki Katamune, Tsuyoshi Yoshitake, Optical and structural characterization of ultrananocrystalline diamond/hydrogenated amorphous carbon composite films deposited via coaxial arc plasma, Current Applied Physics, 10.1016/j.cap.2018.11.012, 19, 2, 143-148, 2019.02, Ultrananocrystalline diamond/hydrogenated amorphous carbon composite films were deposited in the ambient of hydrogen by coaxial arc plasma deposition. The film compositions and chemical bonding structures were investigated by X-ray diffraction, X-ray photoemission and hydrogen forward scattering spectroscopies. The sp 3 /(sp 2 +sp 3 ) ratio and hydrogen content in the film were estimated to be 64% and 35 at.%, respectively. The optical parameters and the optical dispersion profile were determined by using a variable angle spectroscopic ellipsometer at 55° 65° and 75° angle of incidence in the photon energy range of 0.9–5 eV. Combinations of multiple Gaussian, and Tauc-Lorentz or Cody-Lorentz dispersion functions are used to reproduce the experimental data. Results of ellipsometry showed a refractive index of approximately 2.05 (at 2eV) and optical band gap of 1.63 eV. The imaginary part of dielectric function exhibited a peak at 3.8 eV, which has assigned to π-π* electron transitions. Furthermore, Electron spin resonance measurements implied the existence of dangling bonds, which might have a partial contribution to the optical absorption properties of the deposited films. A correlation between optical parameters and structural profile of the deposited films is discussed.. |
| 44. | Mahmoud Shaban, Abdelrahman Zkria, and Tsuyoshi Yoshitake, Characterization and design optimization of heterojunction photodiodes comprising n-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite and p-type Si, Materials Science in Semiconductor Processing, https://doi.org/10.1016/j.mssp.2018.06.028, Vol. 86 (2018) pp. 115-121, 2018.11, . |
| 45. | Rei Fukuta, Naoya Yamamoto, Fumitaro Ishikawa, Masafumi Matsushita, Tsuyoshi Yoshitake, Hiroshi Ikenoue, Hiroaki Ohfuji, Toru Shinmei, Tetsuo Irifune, Pulsed laser irradiation as a process of conductive surface formation on nanopolycrystalline diamond, Japanese Journal of Applied Physics, 10.7567/JJAP.57.118004, 57, 11, 2018.11, We propose a simple and easy electrode formation technique on nanopolycrystalline diamond (NPD) synthesized by a high-temperature and high-pressure technique. The stronger light absorption nature of NPD than of standard transparent diamond enables the laser irradiation process on NPD. Pulsed laser irradiation using an ArF excimer laser under atmospheric condition drastically reduced the resistance of the NPD surface by forming graphite. Repetition of the laser irradiation reduced the resistance, showing a resistance of 300 Ω for the laser-irradiated area of 100 × 150 μm 2 . These results indicate the applicability of pulsed laser irradiation to an NPD apparatus having a conductive electrode, as well as electronic device processes.. |
| 46. | Mahmoud Shaban, Abdelrahman Zkria, and Tsuyoshi Yoshitake, Characterization and design optimization of heterojunction photodiodes comprising n-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite and p-type Si, Materials Science in Semiconductor Processing, https://doi.org/10.1016/j.mssp.2018.06.028, Vol. 86 (2018) pp. 115-121, 2018.11, . |
| 47. | Rawiwan Chaleawpong, Nathaporn Promros, Peerasil Charoenyuenyao, Adison Nopparuchikun, Phongsaphak Sittimart, Tomohiro Nogami, Tsuyoshi Yoshitake, Production of p-Type Si/n-Type β-FeSi2 Heterojunctions Using Facing-Targets Direct-Current Sputtering and Evaluation of Their Resistance and Interface State Density, Physica Status Solidi (A) Applications and Materials Science, 10.1002/pssa.201701022, 215, 20, 2018.10, Without a post-annealing procedure, the β-FeSi2 thin films are epitaxially grown on Si(111) wafer substrates via facing-targets direct-current sputtering. During epitaxial growth, the temperature for heating of substrates is maintained at 600 °C. The resultant p-type Si/n-type β-FeSi2 heterojunctions are produced. At room temperature, a large leakage current under an applied reverse bias voltage together with a small photo-detective performance is observed from the measured dark and irradiated current density–voltage curves of the created heterojunctions. Both of the conductance–voltage (G/ω–V) and capacitance–voltage (C–V) measurements at different frequencies (f) in the range of 5 kHz–1 MHz are performed in the dark at room temperature. The interface state density (Nss) and series resistance (Rs) in the created p-type Si/n-type β-FeSi2 heterojunctions are computed and analyzed from the measured C–V–f and G/ω–V–f curves. Nss is found to be 3.48 × 1012 eV−1 cm−2 at 5 kHz and decreased to 4.68 × 1011 eV−1 cm−2 at 1 MHz. Moreover, the values of Rs at zero bias are 2.21 kΩ at 5 kHz and 13.66 Ω at 1 MHz. These results review the presence of Nss and Rs in the created heterojunctions, and they can be the cause to degrade the heterojunction performance.. |
| 48. | Mohamed Egiza, Hiroshi Naragino, Aki Tominaga, Kenji Hanada, Kazutaka Kamitani, Takeharu Sugiyama, Eiji Ikenaga, Koki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, and Tsuyoshi Yoshitake, Effects of Air Exposure on Hard and Soft X-ray Photoemission Spectra of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films, Coatings, https://doi.org/10.3390/coatings8100359, 2018, 8(10), 359, 2018.10, . |
| 49. | Satoshi Takeichi, Takashi Nishiyama, Mitsuru Tabara, Shuichi Kawawaki, Masamichi Kohno, Koji Takahashi, Tsuyoshi Yoshitake, Hydrogenation effects on thermal conductivity of ultrananocrystalline diamond/amorphous carbon com-posite films prepared by coaxial arc plasma deposition, Appl. Phys. Express, https://doi.org/10.7567/APEX.11.065101, Vol. 11, No. 6 (2018) 065101, 2018.06. |
| 50. | Eslam Abubakr, Yūki Katamune, Abdelrahman Zkria, Hiroshi Ikenoue, Tsuyoshi Yoshitake, Laser-induced phosphorus doping for singlecrystalline diamond in phosphoric acid liquid, J. Phys. Conf. Series, in press, 2018.06. |
| 51. | Hiroki Ishimoto, Kazuki Kudo, Tetsuo Tabei, Kazushi Okada, Shinji Yamada, Tadashi Sato, Ken-ichiro Sakai, Tsuyoshi Yoshitake, Fabrication of lateral-type spin-valve comprising FeSi2 spin-transfer layers by electron beam lithography, J. Phys. Conf. Series, in press, 2018.06. |
| 52. | Weerasaruth Kaenrai, Nathaporn Promros, Phongsaphak Sittimart, Rawiwan Chaleawpong, Peerasil Charoenyuenyao, Thanachai Changcharoen, Adison Nopparuchikun, Tomohiro Nogami, Tsuyoshi Yoshitake, Photovoltaic Properties and Series Resistance of p-Type Si/Intrinsic Si/n-Type Nanocrystalline FeSi2 Heterojunctions Created by Utilizing Facing-Targets Direct-Current Sputtering, Journal of Nanoelectronics and Nanotechnology, in press, 2018.06. |
| 53. | Rawiwan Chaleawpong, Nathaporn Promros, Peerasil Charoenyuenyao, Takanori Hanada, Shinya Ohmagari, Abdelrahman Zkria, Tsuyoshi Yoshitake, Junction parameters of boron-doped p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite/n-type silicon heterojunctions formed by pulsed laser deposition, Journal of Nanoelectronics and Nanotechnology, in press, 2018.06. |
| 54. | Takanori Hanada, Shinya Ohmagari, Abdelrahman Zkria, Tsuyoshi Yoshitake, Photoconduction of p-type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films in Metal-Semiconductor-Metal Geometry, J. Phys. Conf. Series, in press, 2018.06. |
| 55. | Adison Nopparuchikun, Nathaporn Promros, Phongsaphak Sittimart, Peeradon Onsee, Asanlaya Duangrawa, Sakmongkon Teakchaicum, Tomohiro Nogami, Tsuyoshi Yoshitake, Interface-state density estimation of n-type nanocrystalline FeSi2/p-type Si heterojunctions fabricated by pulsed laser deposition, Adv. Nat. Sci.: Nanosci. Nanotechnol., doi:10.1088/2043-6254/aa7241, Vol. 8, No. .3 (2017) 035016, 2018.06. |
| 56. | Naofumi Nishikawa, Satoshi Takeichi, Takanori Hanada, Shuya Tategami, Atsuhiko Fukuyama, Tsuyoshi Yoshitake, Minority carrier lifetime in ultrananocrystalline diamond/hydrogenated amorphous carbon composite films, Trans. Mat. Res. Soc. Jpn, https://doi.org/10.14723/tmrsj.43.49, Vol. 43, issue 2 (2018) pp. 49-52., 2018.02. |
| 57. | Satoshi Takeichi, Takashi Nishiyama, Mitsuru Tabara, Shuichi Kawawaki, Masamichi Kohno, Koji Takahashi, Tsuyoshi Yoshitake, Effects of hydrogenation on thermal transport in ultrananocrystalline diamond/amorphous carbon composite films, Proceedings of 11th International Symposium on Atomic Level Characterizations for New Materials and Devices ’17 (ALC17) Proceedings, pp. 343-345, 2017.12. |
| 58. | Satoshi Takeichi, Naofumi Nishikawa, Shuya Tategami, Atsuhiko Fukuyama, Tsuyoshi Yoshitake, Photodetection properties of heterojunction diodes comprising boron-doped ultrananocrystalline diamond films prepared by coaxial arc plasma deposition and n-type silicon substrates, Proceedings of 11th International Symposium on Atomic Level Characterizations for New Materials and Devices ’17 (ALC17), pp. 346-348, 2017.12. |
| 59. | Mohamed Egiza, Kouki Murasawa, Ali M. Ali, Yasuo Fukui, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Doping Effects of Boron on Mechanical Properties of Ultrananocrystalline Diamond/Amorphous Carbon Com-posite Films Deposited on Cemented Carbide Substrates by Coaxial Arc Plasma Deposition, Proceedings of 11th International Symposium on Atomic Level Characterizations for New Materials and Devices ’17 (ALC17), pp. 368-370, 2017.12. |
| 60. | Kazuki Kudo, S. Takeichi, K. Nakashima, K. Sakai, M. Nishijima, T. Yoshitake, Structural Evaluations of Fe/Boron-Doped Carbon/Fe3Si Spin-Valve Junctions, Proceedings of 11th International Symposium on Atomic Level Characterizations for New Materials and Devices ’17 (ALC17), pp. 64-66, 2017.12. |
| 61. | Kazuki Kudo, S. Takeichi, K. Nakashima, K. Sakai, T. Yoshitake, Magnetoresistance Effects in Spin-Valves Comprising N-Doped Carbon Interlayers (2017) ., Proceedings of 11th International Symposium on Atomic Level Characterizations for New Materials and Devices ’17 (ALC17), pp. 79-81, 2017.12. |
| 62. | Ali M.Ali, Mohamed Egiza, Koki Murasawa, Yasuo Fukui, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Hard Coating of Ultrananocrystalline Diamond/Nonhydrogenated Amorphous Carbon Composite Films on Si Substrates by Coaxial Arc Plasma Deposition, Proceedings of 11th International Symposium on Atomic Level Characterizations for New Materials and Devices ’17 (ALC17), pp. 194-196, 2017.12. |
| 63. | Naofumi Nishikawa, Satoshi Takeichi, Takanori Hanada, Shuya Tategami, Atsuhiko Fukuyama, Tsuyoshi Yoshitake, Minority Carrier Lifetimes in Nitrogen-doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films, Proceedings of the CSS on Energy and Environmental Science and Technology (2017), pp.162-163, 2017.11. |
| 64. | Ali M. Ali, Mohamed Egiza, Koki Murasawa, Yasuo Fukui, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Negative bias effects on the growth and mechanical properties of ultrananocrystaline diamond/amorphous carbon films deposited on cemented carbide substrates by coaxial arc plasma deposition, Proceedings of the CSS on Energy and Environmental Science and Technology (2017), pp. 204-205, 2017.11. |
| 65. | Kazuki Kudo, Satoshi Takeichi, Kazutoshi Nakashima, Ken-ichiro Sakai, Tsuyoshi Yoshitake, Magnetoresistance effects in Fe/nanodiamond/Fe3Si trilayered junctions at room temperature ., Proceedings of the Cross Straits Symposium on Energy and Environmental Science and Technology (2017), pp. 202-203, 2017.11. |
| 66. | Naofumi Nishikawa, Satoshi Takeichi, Shuya Tategami, Atsuhiko Fukuyama, Tsuyoshi Yoshitake, Hydrogenation effects on minority carrier lifetime in ultrananocrystalline diamond/amorphous carbon films prepared by coaxial arc plasma deposition, Proceeding of International Exchange and Innovation Conference on Engineering and Sciences (IEICES 2017), pp. 167-170, 2017.11. |
| 67. | Adison Nopparuchikun, Nathaporn Promros, Phongsaphak Sittimart, Peeradon Onsee, Asanlaya Duangrawa, Sakmongkon Teakchaicum, Tomohiro Nogami, Tsuyoshi Yoshitake, Interface-state density estimation of n-type nanocrystalline FeSi2/p-type Si heterojunctions fabricated by pulsed laser deposition, Advances in Natural Sciences: Nanoscience and Nanotechnology, 10.1088/2043-6254/aa7241, 8, 3, 2017.09, By utilizing pulsed laser deposition (PLD), heterojunctions comprised of n-type nanocrystalline (NC) FeSi2/ thin films and p-type Si substrates were fabricated at room temperature in this study. Both dark and illuminated current density-voltage (J-V ) curves for the heterojunctions were measured and analyzed at room temperature. The heterojunctions demonstrated a large reverse leakage current as well as a weak near-infrared light response. Based on the analysis of the dark forward J-V curves, at the V value ≤ 0.2 V, we show that a carrier recombination process was governed at the heterojunction interface. When the V value was > 0.2 V, the probable mechanism of carrier transportation was a space-charge limitedcurrent process. Both the measurement and analysis for capacitance-voltage-frequency (C-V-f ) and conductance-voltage-frequency (G-V-f ) curves were performed in the applied frequency ( f ) range of 50 kHz-2 MHz at room temperature. From the C-V-f and G-V-f curves, the density of interface states (Nss) for the heterojunctions was computed by using the Hill-Coleman method. The Nss values were 9.19 × 1012 eV-1 cm-2 at 2 MHz and 3.15 × 1014 eV-1 cm-2 at 50 kHz, which proved the existence of interface states at the heterojunction interface. These interface states are the probable cause of the degraded electrical performance in the heterojunctions.. |
| 68. | Abdelrahman Zkria, Tsuyoshi Yoshitake, Temperature-dependent current-voltage characteristics and ultraviolet light detection of heterojunction diodes comprising n-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite films and p-type silicon substrates, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.7567/JJAP.56.07KD04, 56, 7, 2017.07, Heterojunction diodes comprising poorly (1 at. %) nitrogen-doped n-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films and p-type Si substrates were prepared in nitrogen and hydrogen mixed gas atmosphere by coaxial arc plasma deposition. Dark current density-voltage (J-V) characteristics were studied in the temperature range of 200-400 K, in order to investigate the current transport mechanism through the fabricated heterojunctions. The temperature dependence of the ideality factor and reverse saturation current reveals that carrier transport predominantly occurs in the generation-recombination mechanism and, at low temperatures, it accompanies tunneling via weak traps. The heterojunctions surely exhibited photodetection for 254nm ultraviolet light illumination. It is expected that photocarriers will be generated at UNCD grains and transported through an a-C:H matrix.. |
| 69. | Hitoshi Umezawa, Hiroki Gima, Khaled Driche, Yukako Kato, Tsuyoshi Yoshitake, Yoshiaki Mokuno, Etienne Gheeraert, Defect and field-enhancement characterization through electron-beam-induced current analysis, Applied Physics Letters, 10.1063/1.4982590, 110, 18, 2017.05, To investigate the effects of defects and field enhancement in diamond power devices, a biased Schottky barrier diode was characterized by electron-beam-induced current (EBIC) analysis. The nonuniform distribution of the electrical field was revealed by bright spots on the laterally expanded depletion layer of the EBIC intensity map when the applied electrical field exceeded 0.95 MV/cm. The nonuniformity is partly due to a structural effect: the roughness at the edge of the Schottky electrode, induced by lithography and lift-off processes. A second family of spots was shown to increase the leakage current of the device. The time constant associated with this second spot family was 0.98 ms, which is three orders of magnitude shorter than that for defects previously characterized by deep-level transient spectroscopy.. |
| 70. | Kazuki Kudo, Kazutoshi Nakashima, Satoshi Takeichi, Rezwan Ahmed, Seigi Mizuno, Ken-ichiro Sakai, Masahiko Nishijima, Tsuyoshi Yoshitake, Film Structures of Fe/B-doped Carbon/Fe3Si Spin Valve Junctions, JJAP Conf. Proc., doi:10.7567/JJAPCP.5.011502, Vol. 5, 011502, 2017.05. |
| 71. | Kazuya Ishibashi, Kazuki Kudo, Kazutoshi Nakashima, Yuki Asai, Ken-ichiro Sakai, Hiroyuki Deguchi, Tsuyoshi Yoshitake, Temperature-dependent Magnetoresistance Effects in Fe3Si/FeSi2/Fe3Si Trilayered Spin Valve Junctions, JJAP Conf. Proc., doi:10.7567/JJAPCP.5.011501, Vol. 5, 011501, 2017.05. |
| 72. | Tomohiro Nogami, Hirokazu Kishimoto, Ryuji Baba, Nathaporn Promros, Tsuyoshi Yoshitake, Effects of nitrogen doping on optical and electrical properties of nanocrystalline FeSi2 films prepared by sputtering, JJAP Conf. Proc., doi:10.7567/JJAPCP.5.011103, Vol. 5, 011103 , 2017.05. |
| 73. | Takanori Hanada, Shinya Ohmagari, Abdelrahman Zkria, Nathaporn Promros, Tsuyoshi Yoshitake, Photodetection Characteristics of Heterojunctions Comprising p-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films and n-Type Si Substrates at Low Temperatures, Journal of Nanoelectronics and Nanotechnology, DOI: https://doi.org/10.1166/jnn.2017.14104, Vol. 17, No. 5, pp. 3348-3351, 2017.05. |
| 74. | Abdelrahman Zkria, Hiroki Gima, Tsuyoshi Yoshitake, Application of nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films for ultraviolet detection, Applied Physics A: Solids and Surfaces, 10.1007/s00339-017-0798-4, 123, 3, 2017.03, Nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon (UNCD/a-C:H) films were grown by coaxial arc plasma deposition in the ambient of nitrogen and hydrogen mixed gases. Synthesized films were structurally investigated by X-ray photoemission and near-edge X-ray absorption fine structure spectroscopies. A heterojunction with p-type Si substrate was fabricated to study the ultraviolet photodetection properties of the film. Capacitance–voltage measurements assure the expansion of a depletion region into the film side. Current–voltage curves in the dark showed a good rectifying behaviour in the bias voltages range between ±5 V. Under 254 nm monochromatic light, the heterojunction shows a capability of deep ultraviolet light detection, which can be attribute to the existence of UNCD grains. As the diode was cooled from 300 K down to 150 K, the detectivity has a notable enhancement from 1.94 × 105 cm Hz1/2 W−1 at 300 K to 5.11 × 1010 cm Hz1/2 W−1 at 150 K, which is mainly due to a remarkable reduction in the leakage current at low temperatures. It was experimentally demonstrated that nitrogen-doped UNCD/a-C:H film works as ultraviolet-range photovoltaic material.. |
| 75. | Abdelrahman Zkria, Hiroki Gima, Tsuyoshi Yoshitake, Application of nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films for ultraviolet detection, Appl. Phys. A, DOI 10.1007/s00339-017-0798-4, Vol. 123, issue 581, 167 (6 pages), 2017.02. |
| 76. | S. Takeichi, T. Nishiyama, M. Tabara, S. Kawawaki, M. Kohno, K. Takahashi, T. Yoshitake, Thermal conductivity of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition, ECS Transactions, doi: 10.1149/07525.0027ecst, Vol. 75, Issue 25, pp. 27-32, 2017.02. |
| 77. | Y. Katamune, S. Al-Riyami, S. Takeichi, T. Yoshitake, Study on Defects in Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Prepared by Physical Vapor Deposition, ECS Transactions, doi: 10.1149/07525.0045ecst, Vol. 75, Issue 25, pp. 45-52, 2017.02. |
| 78. | Hiroki Gima, Itsuro Suzuki, Tsuyoshi Yoshitake , N-type Conduction in Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition Using Li3PO4-Blended Graphite Targets, ECS Transactions, doi: 10.1149/07525.0037ecst, Vol. 75, Issue 25, pp. 37-44, 2017.02. |
| 79. | Hiroki Gima, Abdelrahman Zkria, Yuki Katamune, Ryota Ohtani, Satoshi Koizumi, Tsuyoshi Yoshitake, Chemical bonding structural analysis of nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by coaxial arc plasma deposition, Applied Physics Express, 10.7567/APEX.10.015801, 10, 1, 2017.01, Nitrogen-doped ultra-nanocrystalline diamond/hydrogenated amorphous carbon composite films prepared in hydrogen and nitrogen mixed-gas atmospheres by coaxial arc plasma deposition with graphite targets were studied electrically and chemical-bonding-structurally. The electrical conductivity was increased by nitrogen doping, accompanied by the production of n-type conduction. From X-ray photoemission, near-edge X-ray absorption fine-structure, hydrogen forward-scattering, and Fourier transform infrared spectral results, it is expected that hydrogen atoms that terminate diamond grain boundaries will be partially replaced by nitrogen atoms and, consequently, φ C-N and C=N bonds that easily generate free electrons will be formed at grain boundaries.. |
| 80. | Abdelrahman Zkria, Mahmoud Shaban, Takanori Hanada, Nathaporn Promros, Tsuyoshi Yoshitake, Current transport mechanisms in n-type ultrananocrystalline diamond/p-type Si heterojunctions, Journal of Nanoscience and Nanotechnology, 10.1166/jnn.2016.13663, 16, 12, 12749-12753, 2016.12, Nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited on p-type Si substrates by coaxial arc plasma deposition. The deposited films possessed n-type conduction, and evidently formed pn heterojunctions with p-type Si substrates. The heterojunction devices showed typical rectification properties similar to those observed for conventional abrupt pn heterojunctions. The conduction mechanisms that govern current transport in these devices were analyzed using dark current-voltage measurements in the temperature range from 300 K to 80 K. The results revealed that a trap-assisted multi-step tunneling process is a dominant mechanism at lower temperatures and low forward bias. At least two defect levels with activation energies of 42 and 24 meV appear to activate this process. At moderate forward bias, the current followed a power-law dependence, attributable to a space-charge-limited current. This junction behavior might be owing to a large number of grain boundaries in the UNCD/a-C:H film that provide active centers for carrier recombination-tunneling processes at the junction interface.. |
| 81. | Hiroki Gima, Tsuyoshi Yoshitake, A Comparative Study of Energy Security in Okinawa Prefecture and the State of Hawaii, Evergreen, Vol. 03, Issue 02, pp. 36-44, 2016.12. |
| 82. | Satoshi Takeichi, Takashi Nishiyama, Mitsuru Tabara, Shuichi Kawawaki, Masamichi Kohno, Koji Takahashi, Tsuyoshi Yoshitake, Thermal Conductivity Measurements of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films by Time-Domain Thermoreflectance, Proceedings of International Forum for Green Asia 2016, pp. 57-58, 2016.12. |
| 83. | Takanori Hanada, Shinya Ohmagari, Abdelrahman Zkria, Tsuyoshi Yoshitake, Barrier Height of Au Contact on p-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films, Proceedings of International Forum for Green Asia 2016, pp. 13-14, 2016.12. |
| 84. | Hiroki Gima, Tsuyoshi Yoshitake, Chemical Bonding Structural Analysis of Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition, Proceedings of International Forum for Green Asia 2016, pp. 11-12, 2016.12, Nitrogen-doped ultra-nanocrystalline diamond/hydrogenated amorphous carbon composite films prepared in hydrogen and nitrogen mixed-gas atmospheres by coaxial arc plasma deposition with graphite targets were studied electrically and chemical-bonding-structurally. The electrical conductivity was increased by nitrogen doping, accompanied by the production of n-type conduction. From X-ray photoemission, near-edge X-ray absorption fine-structure, hydrogen forward-scattering, and Fourier transform infrared spectral results, it is expected that hydrogen atoms that terminate diamond grain boundaries will be partially replaced by nitrogen atoms and, consequently, φ C-N and C=N bonds that easily generate free electrons will be formed at grain boundaries.. |
| 85. | Kazutoshi Nakashima, Kazuki Kudo, Satoshi Takeichi, Ken-ichiro Sakai, Tsuyoshi Yoshitake, Spin valves comprising nitrogen-doped carbon interlayers, Proceedings of the 18th Cross Straits Symposium on Energy and Environmental Science & Technology (2016) , pp. 45-46, 2016.11. |
| 86. | Rezwan Ahmed, Kazuki Kudo, Satoshi Takeichi, Ken-ichiro Sakai, Masahiko Nishijima, Tsuyoshi Yoshitake, Seigi Mizuno, Fabrication of spin valve junctions comprising Fe3Si/B-doped carbon/Fe trilayers , Proceedings of the 18th Cross Straits Symposium on Energy and Environmental Science & Technology (2016), pp. 27-28, 2016.11. |
| 87. | Satoshi Takeichi, Takashi Nishiyama, Mitsuru Tabara, Shuichi Kawawaki, Masamichi Kohno, Koji Takahashi, Tsuyoshi Yoshitake , Thermal conduction evaluation of ultrananocrystalline diamond/hydrogenated amorphous carbon composite films by time-domain thermoreflectance, Proceedings of the 18th Cross Straits Symposium on Energy and Environmental Science & Technology (2016), pp. 31-32, 2016.11. |
| 88. | Adison Nopparuchikun, Nathaporn Promros, Sakmongkon Teakchaicum, Peeradon Onsee, Asanlaya Duangrawa, Phongsaphak Sittimart, Hirokazu Kishimoto, Tomohiro Nogami, Tsuyoshi Yoshitake, C-V-f and G-V-f Characteristics of n-Type β-FeSi2/p-Type Si Heterojunctions Fabricated by Using Radio Frequency Magnetron Sputtering, Proceedings of International Symposium on Dry Process, pp. 129-130, 2016.11. |
| 89. | Mahmoud Shaban, Amr M. Bayoumi, Doaa Farouk, Mohamed B. Saleh, Tsuyoshi Yoshitake, Evaluation of photovoltaic properties of nanocrystalline-FeSi2/Si heterojunctions, Solid-State Electronics, 10.1016/j.sse.2016.05.006, 123, 111-118, 2016.09, In this paper, an application of nanocrystalline iron disilicide (NC-FeSi2) combined with nanocrystalline-Si (NC-Si) in a heterostructured solar cell is introduced and numerically evaluated in detail. The proposed cell structure is studied based on an experimental investigation of photovoltaic properties of NC-FeSi2/crystalline-Si heterojunctions, composed of unintentionally-doped NC-FeSi2 thin film grown on Si substrate. Photoresponse measurement of NC-FeSi2/crystalline-Si heterojunction confirmed ability of NC-FeSi2 to absorb NIR light and to generate photocarriers. However, collection of these carriers was not so efficient and a radical improvement in design of the device is required. Therefore, a modified device structure, comprising of NC-FeSi2 layer sandwiched between two heavily-doped p- and n-type NC-Si, is suggested and numerically evaluated. Simulation results showed that the proposed structure would exhibit a relatively high conversion efficiency of 25%, due to an improvement in collection efficiency of photogenerated carriers in the NC-FeSi2 and NC-Si layers. To attain such efficiency, defect densities in NC-FeSi2 and NC-Si layers should be kept less than 1014 and 1016 cm−3 eV−1, respectively. Remarkable optical and electrical properties of NC-FeSi2, employed in the proposed structure, facilitate improving device quantum efficiency spectrum providing significant spectrum extension into the near-infrared region beyond Si bandgap.. |
| 90. | Hiroshi Naragino, Mohamed Egiza, Aki Tominaga, Koki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Hard coating of ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite films on cemented tungsten carbide by coaxial arc plasma deposition, Applied Physics A: Solids and Surfaces, 10.1007/s00339-016-0284-4, 122, 8, 2016.08, Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite (UNCD/a-C) films were deposited on cemented carbide containing Co by coaxial arc plasma deposition. With decreasing substrate temperature, the hardness was enhanced accompanied by an enhancement in the sp3/(sp2 + sp3). Energy-dispersive X-ray and secondary ion mass spectrometry spectroscopic measurements exhibited that the diffusion of Co atoms from the substrates into the films hardly occurs. The film deposited at room temperature exhibited the maximum hardness of 51.3 GPa and Young’s modulus of 520.2 GPa, which evidently indicates that graphitization induced by Co in the WC substrates, and thermal deformation from sp3 to sp2 bonding are suppressed. The hard UNCD/a-C films can be deposited at a thickness of approximately 3 μm, which is an order larger than that of comparably hard a-C films. The internal compressive stress of the 51.3-GPa film is 4.5 GPa, which is evidently smaller than that of comparably hard a-C films. This is a reason for the thick deposition. The presence of a large number of grain boundaries in the film, which is a structural specific to UNCD/a-C films, might play a role in releasing the internal stress of the films.. |
| 91. | Mahmoud Shaban, Amr M. Bayoumi, Doaa Farouk, Mohamed B. Saleh, Tsuyoshi Yoshitake, Evaluation of photovoltaic properties of nanocrystalline-FeSi2/Si heterojunctions, Solid-State Electronics, in press, in press, 2016.07. |
| 92. | Abdelrahman Zkria, Yuki Katamune, Tsuyoshi Yoshitake, Effects of Nitrogen doping on the electrical conductivity and optical absorption of ultrananocrystalline diamond/hydrogenated amorphous carbon films prepared by coaxial arc plasma dep, Jpn. J. Appl. Phys., http://doi.org/10.7567/JJAP.55.07LE01, Vol. 55, No. 7S2 (2016) 07LE01, 2016.07. |
| 93. | Nathaporn Promros, Ryuji Baba, Motoki Takahara, Tarek M. Mostafa, Phongsaphak Sittimart, Mahmoud Shaban, Tsuyoshi Yoshitake, Epitaxial Growth of beta-FeSi2 Thin Films on Si(111) Substrates by Radio Frequency Magnetron Sputtering and Their Application to Near-Infrared Photodetection, Jpn. J. Appl. Phys., http://doi.org/10.7567/JJAP.55.06HC03, Vol. 55, No. 6S2, 06HC03, 2016.06. |
| 94. | Characterization of n-Type Nanocrystalline Iron Disilicide/Intrinsic Ultrananocrystalline Diamond/Amorphous Carbon Composite/p-type Silicon Heterojuncrion at Low Temperatures, @Nathaporn Promros, #Ryuji Baba, #Hirokazu Kishimoto, @Phongsaphak Sittimart, #Takanori Hanada, @Kenji Hanada, #Abdelrahman Zkria, @Mahmoud Shaban, @Tsuyoshi Yoshitake , J. Nanoelectronics and Optoelectronics, Vol. 11, No. 5 (2016) pp. 579-584, 2016.05. |
| 95. | G. Degutis, P. Pobedinskas, S. Turner, Y. G. Lu, S. Al Riyami, B. Ruttens, Tsuyoshi Yoshitake, J. D'Haen, K. Haenen, J. Verbeeck, A. Hardy, M. K. Van Bael, CVD diamond growth from nanodiamond seeds buried under a thin chromium layer, Diamond and Related Materials, 10.1016/j.diamond.2016.02.013, 64, 163-168, 2016.04, This work presents a morphological and structural analysis of CVD diamond growth on silicon from nanodiamond seeds covered by a 50 nm thick chromium layer. The role of carbon diffusion as well as chromium and carbon silicide formation is analyzed. The local diamond environment is investigated by scanning transmission electron microscopy in combination with electron energy-loss spectroscopy. The evolution of the diamond phase composition (sp3/sp2) is evaluated by micro-Raman spectroscopy. Raman and X-ray diffraction analysis are used to identify the interfacial phases formed during CVD growth. Based upon the observed morphological and structural evolution, a diamond growth model from nanodiamond seeds buried beneath a thin Cr layer is proposed.. |
| 96. | Hiroshi Naragino, Mohamed Egiza, Aki Tominaga, Kouki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Fabrication of ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite films for hard coating by coaxial arc plasma deposition, Evergreen, Vol. 03, Issue 01, pp. 1-5, March 2016, 2016.03. |
| 97. | Mohamed Egiza, Hiroshi Naragino, Aki Tominaga, Kouki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Si and Cr Doping Effects on Growth and Mechanical Properties of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Deposited on Cemented Carbide Substrates by Coaxial Arc Plasma Deposition, Evergreen, http://www.tj.kyushu-u.ac.jp/leading/en/c_publication/EG2016-3-1content/Pages%2032-36.pdf, Vol. 03, Issue 01, pp. 32-36, March 2016, 2016.03. |
| 98. | Hiroshi Naragino, Mohamed Egiza, Aki Tominaga, Kouki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, Room-temperature hard coating of ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite films on tungsten carbide by coaxial arc plasma deposition, Jpn. J. Appl. Phys. (Rapid Communication), http://doi.org/10.7567/JJAP.55.030302, Vol. 55, No. 3, 030302., 2016.01. |
| 99. | Mohamed Egiza, Hiroshi Naragino, Aki Tominaga, Kouki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, DOPING EFFECTS ON ULTRANANOCRYSTALLINE DIAMOND/AMORPHOUS CARBON COMPOSITE FILMS DEPOSITED ON CEMENTED CARBIDE SUBSTRATE BY COAXIAL ARC PLASMA DEPOSITION, Proceedings of The 17th Cross Straits Symposium on Energy and Environmental Science and Technology (CSS-EEST17), pp. 11-12, 2015.12. |
| 100. | Ryuji Baba, Hirokazu Kishimoto, Tarek M. Mostafa, Nathaporn Promros, Tsuyoshi Yoshitake, Current transport mechanisms in n-type ultrananocrystalline diamond/p-type Si heterojunctions, Proceedings of The 17th Cross Straits Symposium on Energy and Environmental Science and Technology (CSS-EEST17), pp. 13-14, 2015.12. |
| 101. | Mohamed Egiza, Hiroshi Naragino, Aki Tominaga, Kouki Murasawa, Hidenobu Gonda, Masatoshi Sakurai, Tsuyoshi Yoshitake, ULTRANANOCRYSTALLINE DIAMOND/AMORPHOUS CARBON COMPOSITE FILMS SYNTHESIS ON CEMENTED CARBIDE SUBSTRATE BY COAXIAL ARC PLASMA DEPOSITION, Proceedings of Intellectual Exchange and Innovation Conference on Engineering & Sciences (IEICES), pp. 23-24, 2015.11. |
| 102. | Takeshi Hara, Kenji Hanada, Tsuyoshi Yoshitake, Detection Methods of Diamond Diffraction Peaks in Ultrananocrystalline diamond?Amorphous Carbon Composite Films by X-ray Diffraction Measurement with Semiconductor Counter Detector, Jpn. J. Appl. Phys, to be published, 2015.11. |
| 103. | Abdelrahman Zkria, Tsuyoshi Yoshitake, Heterojunction Diodes of Nitrogen-Doped Ultrananocrystalline Diamond Films Prepared by Coaxial Arc Plasma Deposition, Proceedings of Intellectual Exchange and Innovation Conference on Engineering & Sciences (IEICES), pp. 21-22, 2015.11. |
| 104. | Nathaporn Promros, Ryuji Baba, Tarek M. Mostafa, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Mechanism of Carrier Transport at Low Temperatures in n-Type β-FeSi2/p-Type Si Heterojunctions Fabricated by Facing-Target Direct-Current Sputtering, Appl. Mech. Mat., doi.org/10.4028/www.scientific.net/AMR.1119.189, Vol. Vol 1119 (2015) pp. 189-193, 2015.10. |
| 105. | Kazuya Ishibashi, Kazutoshi Nakashima, Ken-ichiro Sakai, Tsuyoshi Yoshitake, Magnetic properties of Fe/FeSi2/Fe3Si trilayered films prepared by facing targets sputtering deposition , Conference Proceedings of 68th Annual Gaseous Electronics Conference/9th International Conference on Reactive Plasmas/33rd Symposium on Plasma Processing, GT1.00151, 2015.10. |
| 106. | Abdelrahman Zkria, Tsuyoshi Yoshitake, Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films/p-Silicon heterojunction , Conference Proceedings of 68th Annual Gaseous Electronics Conference/9th International Conference on Reactive Plasmas/33rd Symposium on Plasma Processing, FT4.00006, 2015.10. |
| 107. | Yūki Katamune, Satoshi Takeichi, Shinya Ohmagari, Tsuyoshi Yoshitake, Hydrogenation effects on carrier transport in boron-doped ultrananocrystalline diamond/amorphous carbon films prepared by coaxial arc plasma deposition, J. Vac. Sci. Tech. A, http://dx.doi.org/10.1116/1.4931062, Vol. 6, Issue 6 (2015) 061514., 2015.09, [URL]. |
| 108. | Abdelrahman Zkria, Hiroki Gima, Mahmoud Shaban, Tsuyoshi Yoshitake, Electrical Characteristics of Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition , Appl. Phys. Express, doi:10.7567/APEX.8.095101, Vol. 8, No. 9 (2015) 095101, 2015.09, Nitrogen-incorporated ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were synthesized in nitrogen and hydrogen mixed gas atmospheres by coaxial arc plasma deposition. The temperature dependence of electrical resistivity implies that carriers are transported in hopping conduction. Heterojunctions comprising 3 at.% nitrogen-doped films and p-Si substrates exhibited a typical rectifying action. The expansion of a depletion region into the film side was confirmed from the capacitance–voltage characteristics, and the built-in potential and carrier concentration were estimated to be 0.51 eV and 7.5 ' 1016cm%3, respectively. It was experimentally demonstrated that nitrogen-doped UNCD/a-C:H is applicable as an n-type semiconductor.. |
| 109. | Yūki Katamune, Satoshi Takeichi, Shinya Ohmagari, Hiroyuki Setoyama, Tsuyoshi Yoshitake, Near-Edge X-ray Absorption Fine-Structure Study on Hydrogenated Boron-Doped Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition, Trans. Mat. Res. Soc. Jpn., doi: http://doi.org/10.14723/tmrsj.40.243, Vol. 40, No. 3 (2015) p. 243-246, 2015.08. |
| 110. | Nathaporn Promros, Motoki Takahara, Ryuji Baba, Tarek M. Mostafa, Mahmoud Shaban, Tsuyoshi Yoshitake, Mechanism of Carrier Transport in n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions, Adv. Mat. Res., to be published, 2015.07. |
| 111. | Nathaporn Promros, Dalin Prajakkan, Nantharat Hongsa, Nattanee Suthayanan, Phongsaphak Sittimart, Motoki Takahara, Ryuji Baba, Tarek M. Mostafa, Mahmoud Shaban, Tsuyoshi Yoshitake, Temperature Dependent Current-Voltage Characteristics of n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions, Adv. Mat. Res., doi.org/10.4028/www.scientific.net/AMR.1120-1121.435, Vols. 1120-1121 (2015) pp. 435-439, 2015.07. |
| 112. | Hiroshi Naragino, Aki Tominaga, Kenji Hanada, Tsuyoshi Yoshitake, A synthesis method of ultrananocrystalline diamond in powder employing a coaxial arc plasma gun, Appl. Phys. Express, doi:10.7567/APEX.8.075101, Vol. 8, No. 7 (2015) 075101., 2015.07, A new method that enables us to synthesize ultrananocrystalline diamond (UNCD) in powder is proposed. Highly energetic carbon species ejected from a graphite cathode of a coaxial arc plasma gun were provided on a quartz plate at a high density by repeated arc discharge in a compact vacuum chamber, and resultant films automatically peeled from the plate were aggregated and powdered. The grain size was easily controlled from 2.4 to 15.0nm by changing the arc discharge energy. It was experimentally demonstrated that the proposed method is a new and promising method that enables us to synthesize UNCD in powder easily and controllably.. |
| 113. | Tomohiro Yoshida, Yūtaro Ueda, Takeshi Daio, Aki Tominaga, Toshihiro Okajima, Tsuyoshi Yoshitake, Structural Evaluation of beta-AlN Films Grown on Sapphire (0001) Substrates, Trans. Mat. Res. Soc. Jpn, doi: http://doi.org/10.14723/tmrsj.40.191, Vol. 40, No. 3 (2015) p. 191-194, 2015.07. |
| 114. | Tomohiro Yoshida, Yūtaro Ueda, Takeshi Daio, Aki Tominaga, Toshihiro Okajima, Tsuyoshi Yoshitake, Heteroepitaxial growth of b-AlN films on sapphire (0001) in nitrogen atmospheres by pulse laser deposition, Jpn. J. Appl. Phys., doi:10.7567/JJAP.54.06FJ05, Vol. 54, No. 6S1, 06FJ05., 2015.06. |
| 115. | Abdelrahman Zkria, Hiroki Gima, Sausan Al-Riyami, Tsuyoshi Yoshitake, Fabrication of heterojunction diodes comprising nitrogen-doped ultrananocrystalline diamond/amorphous carbon and p-type silicon., Mater. Res. Soc. Symp. Proc., doi:10.1557/opl.2015.315. , Vol. 1734 (2015), mrsf14-1734-r03-16 (6 pages), 2015.06. |
| 116. | Sausan Al-Riyami, Tsuyoshi Yoshitake, Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Prepared by Laser Ablation of Graphite in Nitrogen and Hydrogen Atmosphere , Adv. Mat. Res., 10.4028/www.scientific.net/AMR.1105.274, Vol. 1105, pp. 274-279., 2015.05. |
| 117. | Nathaporn Promros, Suguru Funasaki, Motoki Takahara, Ryuhei Iwasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Diode Parameters of Mesa Structural n-Type Nanocrystalline FeSi2/p-Type Si Heterojunctions Prepared by Lift-Off Photolithography, Adv. Mat. Res., doi:10.4028/www.scientific.net/AMR.1103.91, Vol. 1103, pp. 91-96., 2015.03. |
| 118. | Nathaporn Promros, Suguru Funasaki, Motoki Takahara, Ryuhei Iwasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Diode Parameters of Mesa Structural n-Type Nanocrystalline FeSi2/p-Type Si Heterojunctions Prepared by Lift-Off Photolithography, Adv. Mat. Res., doi:10.4028/www.scientific.net/AMR.1103.91, Vol. 1103, pp. 91-96., 2015.03. |
| 119. | Kenji Hanada, Tomohiro Yoshida, You Nakagawa, Hiroki Gima, Aki Tominaga, Masaaki Hirakawa, Yoshiaki Agawa, Takeharu Sugiyama, Tsuyoshi Yoshitake, Hardness and modulus of ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by coaxial arc plasma deposition, Appl. Phys. A, doi: 10.1007/s00339-014-8949-3, Vol. 119, Issue 1, pp 205-210. , 2015.02. |
| 120. | Motoki Takahara, Tarek M. Mostafa, Ryuji Baba, Suguru Funasaki, Mahmoud Shaban, Nathaporn Promros, Tsuyoshi Yoshitake, Electric properties of carbon-doped n-type β-FeSi2/p-type Si heterojunction diodes, JJAP Conf. Proc. , doi:10.7567/JJAPCP.3.011101 , Vol. 3, 011101., 2015.02. |
| 121. | Tarek M. Mostafa, Motoki Takahara, Ryuji Baba, Suguru Funasaki, Mahmoud Shaban, Nathaporn Promros, Aki Tominaga, Maiko Nishibori, Tsuyoshi Yoshitake, Epitaxial Growth of n-Type b-FeSi2 Thin Films on p-Type Si(111) Substrates by Radio-Frequency Magnetron Sputtering and Rectifying Action of Heterojunctions, JJAP Conf. Proc. , doi:10.7567/JJAPCP.3.011102 , Vol. 3, 011102., 2015.02. |
| 122. | Yuki Asai, Ken-ichiro Sakai, Kazuya Ishibashi, Kaoru Takeda, Tsuyoshi Yoshitake, Fabrication of Spin Valve Junctions Based on Fe3Si/FeSi2/Fe3Si Trilayered films, JJAP Conf. Proc. , doi:10.7567/JJAPCP.3.011501 , Vol. 3, 011501., 2015.02. |
| 123. | Yuki Asai, Ken-ichiro Sakai, Kazuya Ishibashi, Kaoru Takeda, Tsuyoshi Yoshitake, Spin Valve behavior in Current-Perpendicular-to-Plane Crossover Structural Fe3Si/FeSi2/Fe3Si Trilayered junctions, JJAP Conf. Proc. , doi:10.7567/JJAPCP.3.011504 , Vol. 3, 011504., 2015.02. |
| 124. | Ken-ichiro Sakai, Yuki Asai, Yuta Noda, Takeshi Daio, Aki Tominaga, Kaoru Takeda, Tsuyoshi Yoshitake, Current-induced magnetization switching at low current densities in current-perpendicular-to-plane structural Fe3Si/FeSi2 artificial lattices with various cross-sectional areas, JJAP Conf. Proc. , doi:10.7567/JJAPCP.3.011502, Vol. 3, 011502., 2015.02. |
| 125. | Ken-ichiro Sakai, Yuki Asai, Yuta Noda, Takeshi Daio, Aki Tominaga, Kaoru Takeda, Tsuyoshi Yoshitake, Current-induced magnetization switching at low current densities in current-perpendicular-to-plane structural Fe3Si/FeSi2 artificial lattices with various cross-sectional areas, JJAP Conf. Proc. , doi:10.7567/JJAPCP.3.011502, Vol. 3, 011502., 2015.02. |
| 126. | Tomohiro Yoshida, Kenji Hanada, Hiroki Gima, Ryota Ohtani, Kazushi Sumitani, Hiroyuki Setoyama, Aki Tominaga, Tsuyoshi Yoshitake, Influences of repetition rate of arc discharges on hardness and modules of ultrananocrystalline diamond films prepared by coaxial arc plasma deposition, Mater. Res. Express, doi: 10.1088/2053-1591/2/1/015021, Vol. 2, No.1 (2015) 015021., 2015.01. |
| 127. | Nathaporn Promros, Suguru Funasaki, Motoki Takahara, Ryuhei Iwasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Characterization of Current Transport Mechanism in Heterojunctions Comprising n-Type β-FeSi2 Films and p-Type Si Substrates, Thai Journal of Physics, Series 10, pp. 235-238., 2014.12. |
| 128. | Nathaporn Promros, Suguru Funasaki, Motoki Takahara, Ryuhei Iwasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Characterization of Current Transport Mechanism in Heterojunctions Comprising n-Type β-FeSi2 Films and p-Type Si Substrates, Thai Journal of Physics, Series 10, pp. 235-238., 2014.12. |
| 129. | Hiroki Gima, Tsuyoshi Yoshitake, Heterojunction Diodes Comprising Nitrogen-doped Ultrananocrystalline Dia-mond Films Prepared by Coaxial Arc Plasma Deposition and p-Type Silicon Substrates, Proceedings of International Forum for Green Asia 2014, pp. 17-18., 2014.11. |
| 130. | Takanori Hanada, Tsuyoshi Yoshitake, Photoconduction of B-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films in metal semiconductor metal geometry , Proceedings of International Forum for Green Asia 2014, pp. 19-22., 2014.11. |
| 131. | Hiroshi Naragino, Aki Tominaga, Satoru Hattori, Tsuyoshi Yoshitake, Fabrication of Ultrananocrystalline Diamond Powder by Using A Coaxial Arc Plasma Gun, Proceedings of International Forum for Green Asia 2014, pp. 39-41., 2014.11. |
| 132. | Nathaporn Promros, Motoki Takahara, Ryuji Baba, Tarek M. Mostafa, Suguru Funasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Characterization of Electrical Transport properties in n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions Prepared by Facing Targets Direct-Current Sputtering, Proceeding of The 40th Congress on Science and Technology of Thailand, pp.116-120. , 2014.11. |
| 133. | Nathaporn Promros, Kenji Hanada, Motoki Takahara, Takanori Hanada, Li Chen, Tsuyoshi Yoshitake, Electrical Properties of n-Type Nanocrystalline Iron Disilicide/Intrinsic Ultrananocrystalline Diamond/Amorphous Carbon Composite/p-Type Silicon Heterojunction Photodiodes, Proceeding of The 40th Congress on Science and Technology of Thailand, pp.111-115. , 2014.11. |
| 134. | Nathaporn Promros, Suguru Funasaki, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Diode Parameters of Heterojunctions Comprising p-Type Si Substrate and n-Type β-FeSi2 Thin Films, Advanced Materials Research , Vol. 1043 (2014) pp. 57-61., 2014.09. |
| 135. | Nathaporn Promros, Suguru Funasaki, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Diode Parameters of Heterojunctions Comprising p-Type Si Substrate and n-Type β-FeSi2 Thin Films, Advanced Materials Research , Vol. 1043 (2014) pp. 57-61., 2014.09. |
| 136. | Nathaporn Promros, Suguru Funasaki, Ryuhei Iwasaki, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Investigation of current transport mechanism in mesa structural n-type nanocrystalline-FeSi2/p-type Si heterojunctions, Proc. of The Burapha University International Conference (2014), pp. 438 - 444., 2014.08. |
| 137. | Nathaporn Promros, Suguru Funasaki, Ryuhei Iwasaki, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Near-Infrared Photodetection of Carbon-Doped n-Type Nanocrystalline FeSi2/p-Type Si Heterojunction Photodiodes, Proc. of The Burapha University International Conference (2014), pp. 410 - 415., 2014.08. |
| 138. | Nathaporn Promros, Suguru Funasaki, Ryuhei Iwasaki, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Near-Infrared Photodetection of Carbon-Doped n-Type Nanocrystalline FeSi2/p-Type Si Heterojunction Photodiodes, Proc. of The Burapha University International Conference (2014), pp. 410 - 415., 2014.08. |
| 139. | Nathaporn Promros, Li Chen, Kenji Hanada, Motoki Takahara, Tsuyoshi Yoshitake, Fabrication of n-Type Nanocrystalline Iron Disilicide/Intrinsic Ultrananocrystalline Diamond/Amorphous Carbon Composite/p-Type Silicon Heterojunctions and Their Application to Photodiodes, Proc. on The 1st Engineering Physics Conference, (2014) , pp. 56 - 61., 2014.08. |
| 140. | Kazuki Tsuruta, Masaki Mito, Takuma Nagano, Yuki Katamune, Tsuyoshi Yoshitake, Kazuki Tsuruta, Masaki Mito, Takuma Nagano, Yuki Katamune, and Tsuyoshi Yoshitake Effect of ultrasonic strain on p-type silicon wafers , Jpn. J. Appl. Phys. , doi:10.7567/JJAP.53.07KC07, Vol. 53, No. 7S. (2014) 07KC07., 2014.07. |
| 141. | Shinya Ohmagari, Takanori Hanada, Yūki Katamune, Sausan Al-Riyami, Tsuyoshi Yoshitake, Carrier Transport and Photodetection in Heterojunction Photodiodes Comprising n-Type Silicon and p-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films, Jpn. J. Appl. Phys. , 10.7567/JJAP.53.050307, Vol. 53, No. 5, 050307, 2014.05. |
| 142. | Ken-ichiro Sakai, Yuta Noda, takeshi Daio, Daiki Tsumagari, Aki Tominaga, Kaoru Takeda, Tsuyoshi Yoshitake, Current-induced Magnetization Switching at Low Current Densities in CPP Structural Fe3Si/FeSi2 Artificial Lattices, Jpn. J. Appl. Phys. , 10.7567/JJAP.53.02BC15, Vol. 53, Issue 2S, 02BC15, 2014.02. |
| 143. | Ken-ichiro Sakai, Yuta Noda, Daiki Tsumagari, Hiroyuki Deguchi, Kaoru Takeda, Tsuyoshi Yoshitake, Temperature-Dependent Interlayer coupling in Fe3Si/FeSi2 artificial lattices, Phys. Status Solidi A, 10.1002/pssa.201330116, Vol. 211, No. 2, 323-328, 2014.02. |
| 144. | Ken-ichiro Sakai, Yuki Asai, Yuta Noda, Kaoru Takeda, Tsuyoshi Yoshitake, The fabrication of new spin devices by Fe3Si/FeSi2/Fe3Si trilayer films, Proc. of the 8th Int. Conf. on Reactive Plasmas and 31th Symp. on Plasma Proc., 6P-AM-S10-P50, 2014.02. |
| 145. | Nathaporn Promros, Ryūhei Iwasaki, Suguru Funasaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Temperature Dependent Current-Voltage Characteristics of n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunctions Fabricated by Pulsed Laser Deposition, Advanced Materials Research, 10.4028/www.scientific.net/AMR.858.171, Vol. 858 (2014) pp. 171-176, 2014.01. |
| 146. | Ken-ichiro Sakai, Yuta Noda, Kaoru Takeda, Masayasu Takeda, Tsuyoshi Yoshitake, Magnetoresistance Effects in Current-Perpendicular-to-Plane Structures based on Fe3Si/FeSi2 artificial lattices, Phys. Status Solidi C, 10.1002/pssc.201300322, Vol. 10, No. 12, pp. 1862-1865, 2013.12. |
| 147. | Suguru Funasaki, Nathaporn Promros, Ryuhei Iwasaki, Motoki Takahara, Mahmoud Shaban, Tsuyoshi Yoshitake, Fabrication of mesa structural n-type nanocrystalline-FeSi2/p-type Si heterojunction photodiodes by liftoff technique combined with photolithography, Phys. Status Solidi C, 10.1002/pssc.201300346, Vol. 10, No. 12, pp. 1785-1788., 2013.12. |
| 148. | Yūki Katamune, Tsuyoshi Yoshitake, Optical and Electrical Properties of Boron-doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition, Proceedings of The 15th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 70-71, 2013.11. |
| 149. | Suguru Funasaki, Ryuhei Iwasaki, Nathaporn Promros, Mahmoud Shaban, Tsuyoshi Yoshitake, Electrical Properties of Mesa Structural n-type Nanocrystalline-FeSi2/p-type Si Heterojunction Photodiodes, Proceedings of The 15th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 68-69, 2013.11. |
| 150. | Hiroki Gima, Tsuyoshi Yoshitake, Fabrication of n-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by coaxial arc plasma deposition (II), Proceedings of The 15th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 48-49, 2013.11. |
| 151. | Takanori Hanada, Shinya Ohmagari, Tsuyoshi Yoshitake, Metal-Semiconductor-Metal Photodetection of Boron-doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films, Proceedings of The 15th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 46-47, 2013.11. |
| 152. | Nathaporn Promros, Suguru Funasaki, Ryūhei Iwasaki, Tsuyoshi Yoshitake, Electrical Characteristics of n-Type Nanocrystalline FeSi2/Intrinsic Si/p-Type Si Heterojunctions Prepared by Facing-Targets Direct-Current Sputtering . , Applied Mechanics and Materials, Vol. 446-447 (2014) pp. 88-92, 2013.11. |
| 153. | Nathaporn Promros, Suguru Funasaki, Ryūhei Iwasaki, Tsuyoshi Yoshitake, Electrical Characteristics of n-Type Nanocrystalline FeSi2/Intrinsic Si/p-Type Si Heterojunctions Prepared by Facing-Targets Direct-Current Sputtering . , Applied Mechanics and Materials, Vol. 446-447 (2014) pp. 88-92, 2013.11. |
| 154. | Sausan Al-Riyami, Hiroki Gima, Hiroshi Akamine, Tsuyoshi Yoshitake, Chemical Bonding of Nitrogenated Ultrananocrystalline Diamond Films Deposited on Titanium Substrates by Pulsed Laser Deposition, ECS J. Solid State Sci. Technol., 10.1149/2.016311jss, Vol. 2, issue 11 (2013) M33-38, 2013.11. |
| 155. | Nathaporn Promros, Chen Li, Suguru Funasaki, Ryūhei Iwasaki, Motoki Takahara, Tsuyoshi Yoshitake, Nathaporn Promros, Chen Li, Suguru Funasaki, Ryūhei Iwasaki, Motoki Takahara, Tsuyoshi Yoshitake, Proceeding of The 39th Congress on Science and Technology of Thailand, pp. 91-94, 2013.11. |
| 156. | Nathaporn Promros, Suguru Funasaki, Ryūhei Iwasaki, Tsuyoshi Yoshitake, Current Transport Mechanism of n-Type Nanocrystalline FeSi2/Intrinsic Si/p-Type Si Heterojunctions Fabricated by Facing-Targets Direct-Current Sputtering, Advanced Materials Research, 10.4028/www.scientific.net/AMR.802.199, Vol. 802 (2013) pp. 199-203, 2013.09. |
| 157. | Nathaporn Promros, Ryūhei Iwasaki, Suguru Funasaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Characterizations of Mesa Structural Near-Infrared n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunction Photodiodes at Low Temperatures, Advanced Materials Research, 10.4028/www.scientific.net/AMR.747.217, Vol. 747 (2013) pp. 217-220, 2013.08. |
| 158. | Yutaro Ueda, Takeshi Daio, Tomohiro Yoshida, Aki Tominaga, Toshihiro Okajima, Tsuyoshi Yoshitake, Crystalline-Structural Evaluations of Cubic AlN Thin Films Heteroepitaxially Grown on Sapphire(0001) by Pulsed Laser Deposition , Jpn. J. Appl. Phys., 10.7567/JJAP.52.08JE03, Vol. 52, No. 8 (2013) 08JE03., 2013.06, [URL], Cubic β-AlN thin films with different thicknesses were grown on sapphire (0001) in nitrogen atmosphere by pulsed laser deposition with sintered AlN targets, and their film structures were evaluated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was found that β-AlN layers with a lattice constant of 7.89 Å are epitaxially grown on sapphire (0001) with a relationship of βAlN(111)[111]∥Al2O3(0001)[1100] at film thicknesses of less than 20 nm, and at larger thicknesses, polycrystalline β-AlN grains are grown on the epitaxial β-AlN layers in the Stranski–Krastanov (SK) mode. . |
| 159. | Sausan Al-Riyami, Hiroki Gima, Tsuyoshi Yoshitake, Effects of Hydrogen and Nitrogen Atmospheres on Growth of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films by Reactive Pulsed Laser Deposition, Jpn. J. Appl. Phys., 10.7567/JJAP.52.06GG06, Vol. 52, No. 6 (2013) 06GG06., 2013.06, [URL], The growth of ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite films was realized by pulsed laser deposition with a graphite target in a nitrogen atmosphere totally excluding hydrogen. The existence of 7 nm diamond grains was confirmed by X-ray diffraction. Nitrogen incorporation into the films was confirmed by X-ray photoemission and near-edge X-ray absorption structure spectroscopies, and the nitrogenation produced n-type conduction with an electrical conductivity of 0.2 Ω-1· cm-1 at 300 K. The results of study proved that nitrogen acts as a reactive gas for the formation of diamond grains, similarly to hydrogen. . |
| 160. | Yuki Katamune, Shinya Ohmagari, Sausan Al-Riyami, Seishi Takagi, Mahmoud Shaban, Tsuyoshi Yoshitake, Heterojunction Diodes Comprising p-Type Ultrananocrystalline Diamond Films Prepared by Coaxial Arc Plasma Deposition and n-Type Silicon Substrates , Jpn. J. Appl. Phys., 10.7567/JJAP.52.065801, Vol. 52, No. 6 (2013) 065801., 2013.06, [URL], Heterojunction diodes, which comprise boron-doped p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films prepared by coaxial arc plasma deposition and n-type Si substrates, were electrically studied. The current–voltage characteristics showed a typical rectification action. An ideality factor of 3.7 in the forward-current implies that carrier transport is accompanied by some processes such as tunneling in addition to the generation–recombination process. From the capacitance–voltage measurements, the built-in potential was estimated to be approximately 0.6 eV, which is in agreement with that in a band diagram prepared on the assumption that carriers are transported in an a-C:H matrix in UNCD/a-C:H. Photodetection for 254 nm monochromatic light, which is predominantly attributable to photocurrents generated in UNCD grains, was evidently confirmed in heterojunctions. Since dangling bonds are detectable by electron spin resonance spectroscopy, their control might be an important key for improving the rectifying action and photodetection performance. . |
| 161. | Nathaporn Promros, Li Chen, Tsuyoshi Yoshitake, Evaluation of n-Type Nanocrystalline FeSi2/p-Type Si Heterojunctions Prepared by Pulsed Laser Deposition as Near-Infrared Photodetectors, J. Nanosci. Nanotechnol. , 10.1166/jnn.2013.7311, Vol. 13, No. 5 (2013) pp. 3577–3581., 2013.05, n-Type nanocrystalline (NC) FeSi2/p-type Si heterojunctions, which were prepared by pulsed laser deposition, were evaluated as a near infrared photodiode. The built-in potential was estimated to be approximately 1.1 eV from the capacitance–voltage measurement. These junctions showed a rectifying behavior accompanied by a large leakage current. The near infrared light detection performance was evaluated using a 1.33 m laser in the temperature range of 77–300 K. At a reverse bias of −5 V, the detectivity was 55×107 cm Hz1/2 W−1 at 300 K and it was dramatically enhanced to be 80×1010 cm Hz1/2 W−1 at 77 K. It was demonstrated that NC-FeSi2 is a new potential material applicable to NIR photodetectors operating at low temperatures.. |
| 162. | Yuki Katamune, Shinya Ohmagari, Hiroyuki Setoyama, Kazuishi Sumitani, Yasuharu Hirai, Tsuyoshi Yoshitake, Formation of n-Type Ultrananocrystalline Diamond/Nonhydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition with Boron-Incorporated Graphite Targets, ECS Transactions, 10.1149/05020.0023ecst, Vol. 50, issue 20 (2013) pp. 23-28, 2013.04, Boron-doped ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite (UNCD/a-C) films were prepared by coaxial arc plasma deposition (CAPD) with boron-blended graphite target. Their growth was achieved at room temperature and a base pressure of less than 10-3 Pa (no inflow gas) owing to CAPD, whereas the growth of UNCD films by chemical vapor deposition generally requires high substrate temperatures of more than 700°C and a hydrogen ambient gas. The formation of p-type conduction was confirmed thermally, namely Seebeck effect, and heterojunction diodes formed with n-type Si exhibited a typical rectifying action. It was demonstrated that CAPD is advantageous to the practical film formation including doping.. |
| 163. | Sausan Al-Riyami, Hiroyuki Setoyama, Kazuishi Sumitani, Yasuharu Hirai, Tsuyoshi Yoshitake, Nitrogenation Effects on n-Type Electrical Conductivity of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed Laser Deposition, ECS Transactions, 10.1149/05022.0041ecst , Vol. 50, issue 20 (2013) pp. 41-47, 2013.04, Nitrogenated ultrananocrystalline diamond/hydrogenated amorphous carbon composite films were prepared in a hydrogen and nitrogen mixed-gas atmosphere by pulsed laser deposition with graphite targets. The electrical conductivity in n-type conduction remarkably increases to 18 §Ù–1×cm–1 at 300 K with an increase in the nitrogen content up to 7.9 at.%. In the nitrogen content range from 7.9 to 10.4 at.%, the electrical conductivity is suddenly and dramatically decreased down to 0.03 §Ù–1·cm–1 in reverse, accompanied by the disappearance of diamond grains in the films. A huge number of grain boundaries owing to the existence of diamond grains embedded in UNCD/a-C:H films, which is structural specific to UNCD/a-C:H, should play a significant role in the large electrical conductivity enhancement by nitrogen doping. The X-ray photoemission and near-edge X-ray fine-absorption spectroscopic measurements could not detect an evident difference in the spectra that explain the sudden irregular change in the electrical conductivity. . |
| 164. | Sausan Al-Riyami, Tsuyoshi Yoshitake, Nitrogenated Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Deposited on Titanium Substrates by Pulsed Laser Deposition , ECS Transactions, 10.1149/05022.0013ecst , Vol. 50, issue 20 (2013) pp.13-20, 2013.04, Nitrogenated ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite (UNCD/a-C) films were deposited on titanium in a nitrogen atmosphere by laser pulsed deposition. The adhesion between the films and titanium substrates were remarkably improved as compared with those between hydrogenated (UNCD/a-C) films and titanium substrates. X-ray photoemission and near edge X-ray absorption structure measurements indicated an increase in the sp2 and sp bonding fraction such as C=N double and triple bonds by nitrogenation. Since they locally disconnect tetrahedral bonding in the films and expected to release an internal stress in the films, the film adhesion might be improved. . |
| 165. | Shotra Izumi, Mahmoud Shaban, Nathaporn Promros, Keita Nomoto, Tsuyoshi Yoshitake, Near-Infrared Photodetection of beta-FeSi2/Si Heterojunction Photodiodes at Low Temperatures , Appl. Phys. Lett., http://dx.doi.org/10.1063/1.4789391, Appl. Phys. Lett. Vol. 102, Issue 3 (2013) 032107, 2013.02, n-type b-FeSi2/p-type Si heterojunction photodiodes were fabricated by facing-targets direct-current sputtering, and their near-infrared photodetection properties were studied in the temperature range of 50–300 K. At 300K, devices biased at 5V exhibited a current responsivity of 16.6mA/W. The measured specific detectivity was remarkably improved from 3.5109 to 1.41011 cmHz1/2/W as the devices were cooled from 300K down to 50 K. This improvement is mainly attributable to distinguished suppression in heterojunction leakage current at low temperatures. The obtained results indicate that b-FeSi2/Si heterojunctions offer high potential to be employed as near-infrared photodetectors that are compatible with the current Si technology. V. |
| 166. | Ryuhei Iwasaki, Nathaporn Promros, Kyohei Yamashita, Shota Izumi, Suguru Funasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Necessity of Epitaxial Growth of b-FeSi2 Thin Films in Formation of n-Type β-FeSi2/p-Type Si Heterojunction Photodiodes, ECS Transactions, 10.1149/05006.0157ecst, Vol. 50, issue 6 (2013) pp. 157-162, 2013.01. |
| 167. | Yuta Noda, Ken-ichiro Sakai, Takayuki Sonada, Daiki Tsumagari, Kaoru Takeda, Tsuyoshi Yoshitake, Fabrication of Current-Perpendicular-to-Plane Junctions Based on Fe3Si/FeSi2 Multilayered Films by Lift-Off , ECS Transactions, 10.1149/05010.0223ecst, Vol. 50, issue 10 (2013) pp. 223-228, 2013.01. |
| 168. | E. Garratt, S. AlFaify, Tsuyoshi Yoshitake, Yuki Katamune, M. Bowden, M. Nandasiri, M. Ghantasala, D. C. Mancini, S. Thevuthasan, A. Kayani, Effect of chromium underlayer on the properties of nano-crystalline diamond films, Appl. Phys. Lett., http://dx.doi.org/10.1063/1.4774086, No. 102, Issue 1 (2012) 011913., 2013.01, [URL], This paper investigated the effect of chromium underlayer on the structure, microstructure, and composition of the nano-crystalline diamond films. Nano-crystalline diamond thin films were deposited at high temperature in microwave-induced plasma diluted with nitrogen, on single crystal silicon substrate with a thin film of chromium as an underlayer. Characterization of the film was implemented using non-Rutherford backscattering spectrometry, Raman spectroscopy, near-edge x-ray absorption fine structure, x-ray diffraction, and atomic force microscopy. Nanoindentation studies showed that the films deposited on chromium underlayer have higher hardness values compared to those deposited on silicon without an underlayer. Diamond and graphitic phases of the films evaluated by x-ray and optical spectroscopic analyses determined consistency between the sp2 and sp3 phases of carbon in chromium sample to that of diamond grown on silicon. Diffusion of chromium was observed using ion beam analysis which was correlated with the formation of chromium complexes by x-ray diffraction.. |
| 169. | Ryuhei Iwasaki, Kyohei Yamashita, Nathaporn Promros, Shota Izumi, Suguru Funasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Near-Infrared Light Detection of n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunction Photodiodes at Low Temperatures, ECS Transactions, 10.1149/05006.0129ecst, Vol. 50, issue 6 (2013) pp. 129-135., 2013.01. |
| 170. | Nathaporn Promros, Ryuhei Iwasaki, Suguru Funasaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Preparation of Mesa Structural Near-Infrared n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunction Photodiodes, Proc. of The 15th International Conference of International Academy of Physical Sciences, pp. 95-100., 2012.12. |
| 171. | Mahmoud Shaban, Tsuyoshi Yoshitake, Interface Properties of Nanocrystalline-FeSi2/Crystalline-Si Near-Infrared Heterojunction Photodiodes, IEEE J. Quantum Electrionics, Vol. 48, No. 11 (2012) pp. 1432-1438, 2012.11. |
| 172. | Nathaporn Promros, Kyohei Yamashita, Ryuhei Iwasaki, Tsuyoshi Yoshitake, Effects of Hydrogen Passivation on Near-Infrared Photodetection of n-Type -FeSi2/p-Type Si Heterojunction Photodiodes, Jpn. J. Appl. Phys. , http://dx.doi.org/10.1143/JJAP.51.108006, Vol. 51, No. 10 (2012) 108006., 2012.10, Hydrogen passivation was applied to the initial epitaxial growth of n-type -FeSi2 thin films on p-type Si(111) substrates. Such passivation was applied at different gas inflow H2/Ar ratios ranging from 0 to 1.0. The photodetection performance of the photodiode fabricated at the optimum ratio of 0.2 was markedly improved as compared with those of the other samples. The quantum efficiency and detectivity were 2.08% and 5:40 109 cmHz1=2W1, respectively. The enhanced photodetective performance should be mainly because dangling bonds that act as trap centers for photocarriers are effectively inactivated by the passivation.. |
| 173. | , [URL]. |
| 174. | Nathaporn Promros, Kyohei Yamashita, Shota Izumi, Ryu¯hei Iwasaki, Mahmoud Shaban, Tsuyoshi Yoshitake, Near-Infrared Photodetection of n-Type β-FeSi2/intrinsic Si/p-Type Si Heterojunctions at low temperatures, Jpn. J. Appl. Phys. , http://dx.doi.org/10.1143/JJAP.51.09MF02, Vol. 51, No. 9 (2012) 09MF02., 2012.09. |
| 175. | Shinya Ohmagari, Tsuyoshi Yoshitake, p-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed Laser Deposition and Their Application to Photodetectors, Jpn. J. Appl. Phys., http://dx.doi.org/10.1143/JJAP.51.090123, Vol. 51, No. 9, (2012) 090123 (Selected Topics in Applied Physics), 2012.07. |
| 176. | Yuki Katamune, Shinya Ohmagari, Tsuyoshi Yoshitake, Boron-Induced Dramatically Enhanced Growth of Diamond Grains in Nanocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films deposition by Coaxial Arc Plasma Deposition, Jpn. J. Appl. Phys., 10.1143/JJAP.51.078003, Vol. 51, No. 7 (2012) 078003., 2012.07, [URL], Boron-doped nanocrystalline diamond/hydrogenated amorphous carbon composite films were prepared by coaxial arc plasma deposition. The X-ray diffraction measurement exhibited that the diamond grain size is remarkably increased from 2 nm (undoped films) to 82 nm and the lattices of the grains are dilated accompanied by the incorporation of boron atoms into the lattices. The near-edge X-ray absorption fine-structure showed a weak exciton peak of diamond due to the enlarged grains. The enhanced growth mechanism is discussed on the basis of a defect-induced diamond growth model. . |
| 177. | Yoji Akaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Shigeuki Nakamura, Satoru Seto, Takahiro Tokuda, Kenji Yoshino, Characterization of AgInS2 thin films prepared by vacuum evaporation, Physica B: Condensed Matter, 10.1016/j.physb.2011.12.119, Vol. 407, Issue 15 (2012) pp. 2858-2860., 2012.07. |
| 178. | Yuki Katamune, Shinya Ohmagari, Itsuroh Suzuki, Tsuyoshi Yoshitake, Effects of Aluminum Incorporation on Diamond Grain Growth in Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition, Jpn. J. Appl. Phys., 10.1143/JJAP.51.068002, Vol. 51, No. 6 (2012) 068002., 2012.06, [URL], Al-incorporated ultrananocrystalline diamond/hydrogenated amorphous carbon composite films were prepared by coaxial arc plasma deposition with an Al-blended graphite target. The grain size estimated from X-ray diffraction peaks was 27 nm; this value is an order of magnitude larger than that of unincorporated films. The appearance of diamond-200 and 222 peaks, which generally disappear due to the extinction rule of diffraction, and the dilation of lattice, implied the incorporation of Al atoms into the lattices. The near-edge X-ray absorption fine-structure showed a sharp exciton peak due to diamond, which is attributed to the enlarged grains. . |
| 179. | Shinya Ohmagari, Tsuyoshi Yoshitake, Deep-Ultraviolet Light Detection of p-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films, Appl. Phys. Express, 10.1143/APEX.5.065202, Vol. 5, No. 6 (2012) 065202., 2012.06, [URL], Deep-ultraviolet (DUV) light detection of p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films prepared by pulsed laser deposition was investigated. The photocurrent spectra revealed that the UNCD/a-C:H films possess strong responses in the wavelength range between 210 and 280 nm, which might originate from UNCD grains. The heterojunction photodiodes comprised of p-type UNCD/a-C:H and n-type Si exhibited an obvious photovoltaic action for 254 nm DUV light illumination. The external quantum efficiency and responsivity of the photodiodes were estimated to be 71% and 130 mA/W, respectively. It was proved that UNCD/a-C:H is a new promising material applicable to DUV photodetectors.. |
| 180. | Yoji Akaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Shigeuki Nakamura, Takahiro Tokuda, Kenji Yoshino, Effect of H2S Annealing on Ag-Rich Ag–In–S Thin Films Prepared by Vacuum Evaporation, Jpn. J. Appl. Phys., Vol. 50, No. 5 (2011) 05FB06. , 2012.05. |
| 181. | Hirotoshi Mori, Yosuke Odahara, Daisuke Shigyo, Tsuyoshi Yoshitake, Eisaku MIYOSHI, Electronic Band Structure Calculations on Thin Films of the L21 Full Heusler Alloys X2YSi (X, Y = Mn, Fe, and Co): toward Spintronic Materials, Thin Solid Films
, 10.1016/j.tsf.2012.03.045, Vol. 520, Issue 15 (2012) pp. 4979-4983, 2012.04, To design half-metallic materials in thin film form for spintronic devices, the electronic structures of full Heusler alloys (Mn2FeSi, Fe2MnSi, Fe2FeSi, Fe2CoSi, and Co2FeSi) with an L21 structure have been investigated using density functional theory calculations with Gaussian-type functions in a periodic boundary condition. Considering the metal composition, layer thickness, and orbital symmetries, a 5-layered Co2FeSi thin film, whose surface consists of a Si layer, was found to have stable half-metallic nature with a band gap of ca. 0.6 eV in the minority spin state. Using the group theory, the difference between electronic structures in bulk and thin film conditions was discussed.. |
| 182. | Aki Tominaga, Kenji Hanada, Tomohiro Yoshida, and Tsuyoshi Yoshitake, Preparation of Diamond Nanocrystallites in Powder by Using a Coaxial Arc Plasma Gun, Mater. Res. Symp. Proc., 10.1557/opl.2012.532, Vol. 1395 (2012) mrsf11-1395-n12-30 (6 pages)., 2012.03, [URL], We suggest a new method for fabricating diamond nanoclusters by employing a coaxial arc plasma gun. Diamond powder comprised of diamond nanoclusters and amorphous carbon was fabricated in vacuum and a hydrogen atmosphere, and the diamond crystallite sizes were estimated to be 1.8, 2.3, and 2.3 nm for the powders prepared at hydrogen pressures of 0, 53.3, and 159.6 Pa respectively, from the X-ray diffraction peaks. The hydrogen ambient gas is not necessarily required for the diamond nanoclusters formation. We consider that this method enables us to form diamond nanoclusters in nucleation owing to a supersaturated condition at a facing plate located in front of an arc plasma gun.. |
| 183. | Shinya Ohmagari, Yūki Katamune, Hikaru Ichinose, and Tsuyoshi Yoshitake, "Enhanced growth of diamond grains in ultrananocrystalline diamond/hydrogenated amorphous carbon composite films by pulsed laser deposition with boron-blended graphite targets", Jpn. J. Appl. Phys., 10.1143/JJAP.50.035101, Vol. 51, No. 2 (2012) 025503., 2012.02, [URL], Heterojunction diodes comprised of p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) and n-type Si, wherein 3 at. % boron-doped UNCD/a-C:H films were deposited on Si substrates by pulsed laser deposition, were electrically studied. The current–voltage (I–V) characteristics showed the typical rectification action with a leakage current density of 4.7 ×10-5 A/cm2 at a reverse voltage of -1 V. The carrier transport is expected to be in generation–recombination process accompanied by tunneling at low forward voltages of 0.1–0.5 V, and to be predominantly in tunneling at 0.5–1.0 V, from ideality factors estimated from the forward I–V curve. Grain boundaries in the UNCD/a-C:H film might act as centers for tunneling. From the capacitance–voltage measurement, the build-in potential of the heterojunction and an active carrier concentration in the p-type UNCD/a-C:H film were estimated to be 0.6 eV and 1.4 ×1017 cm-3, respectively. . |
| 184. | Ken-ichiro Sakai, Takayuki Sonoda, Shin-ichi Hirakawa, Kaoru Takeda, and Tsuyoshi Yoshitake, Current-Induced Magnetization Switching in Fe3Si/FeSi2 Artificial Lattices, Jpn. J. Appl. Phys., 10.1143/JJAP.50.08JD06, Vol. 51, No. 2 (2012) 028004., 2012.02, [URL], Fe3Si/FeSi2/Fe3Si trilayered films were grown on Si(111) substrates at a substrate temperature of 300 °C by facing-targets direct-current sputtering, and current-induced magnetization switching in current-perpendicular-to-plane geometry was studied for the films wherein an antiferromagnetic interlayer coupling perpendicular to the plane was probably formed at room temperature. The appearance of a hysteresis loop in the electrical resistance–injection current curve well coincided with that of a hysteresis loop in the magnetization curve perpendicular to the plane. In addition, the hysteresis loop in the electrical resistance–injection current curve disappeared under large magnetic fields. The origin of the change in the electrical resistance for the injection current might be the change in the interlayer coupling. . |
| 185. | Nathaporn Promros, Kyohei Yamashita, Chen Li, Kenji Kawai, Mahmoud Shaban, Toshihiro Okajima, and Tsuyoshi Yoshitake, n-Type Nanocrystalline FeSi2/intrinsic Si/p-Type Si Heterojunction Photodiodes fabricated by Facing-Targets Direct-Current Sputtering, Jpn. J. Appl. Phys., 10.1143/JJAP.51.021301, Vol. 51, No. 2 (2012) 021301., 2012.01, [URL], n-Type nanocrystalline (NC) FeSi2/intrinsic (i) Si/p-type Si heterojunctions, which were prepared by facing-target direct current sputtering, were evaluated as near-infrared photodiodes, and the effects of thin i-Si layer insertion on diode performance were studied. Their junction capacitance and reverse leakage current were clearly reduced compared with those of n-type NC-FeSi2/p-type Si heterojunctions. The capacitance–voltage curve implied that the effects of interface states is relatively suppressed by i-Si insertion. The near-infrared light detection performance was investigated using a 1.33 µm laser in the temperature range of 77–300 K. The detectivities at 300 and 77 K were 1.9 ×108 and 3.0 ×1011 cm Hz1/2 W-1, respectively, at a negative bias of -5 V, which were markedly improved compared with that of p–n heterojunctions. This might be because the formation of interface states that act as trap centers for photocarriers is suppressed. . |
| 186. | Kyohei Yamashita, Nathaporn Promros, Ryūhei Iwasaki, Shota Izumi and Tsuyoshi Yoshitake, Influences of hydrogen passivation on NIR photodetection of n-type β-FeSi2/p-type Si heterojunction photodiodes fabricated by facing-targets direct-current sputtering, Mater. Res. Symp. Proc., 10.1557/opl.2012.84, Vol. 1396 (2012) mrsf11-1396-o07-18 (6 pages), 2012.01, [URL], Hydrogen passivation was applied to the initial epitaxial growth of n-type β-FeSi2 thin films on p-type Si(111) substrates by facing-targets direct-current sputtering (FTDCS) in order to reduced the formation of interface states and terminate dangling bonds in the β-FeSi2 films, and the passivation effects were studied on basis of the electrical evaluation results of the formed n-type β-FeSi2/p-type Si heterojunction photodiodes. The initial growth was made at different gas inflow H2/Ar ratios ranging from 0 to 0.2. The photodetection performance of the photodiode fabricated at the ratio of 0.2 was markedly improved as compared to those of the other samples. The quantum efficiency and detectivity were 2.08 % and 1.75 × 1010 cm√Hz/W, respectively. The sample exhibited the minimum junction capacitance density of 9.2 nF/cm2. The enhanced photodetective performance should be mainly because dangling bonds that act as trap centers for photocarriers are effectively inactivated by the passivation.. |
| 187. | Shinya Ohmagari, Yūki Katamune, Hikaru Ichinose and Tsuyoshi Yoshitake, Roles of boron in growth of diamond grains in ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by pulsed laser deposition, Mater. Res. Symp. Proc., 10.1557/opl.2012.339, Vol. 1395 (2012) mrsf11-1395-n12-17 (6 pages), 2012.01, [URL], Boron doped ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon composite films prepared by pulsed laser deposition were structurally investigated. With an increase in the boron content, the grain size was increased from 5 to 23 nm accompanying by the lattice constant approaching to that of bulk diamond. The near-edge X-ray absorption fine-structure revealed that boron atoms are preferentially distributed into grain boundaries. On the basis of the results, the roles of the boron atoms in the enhanced crystalline growth are discussed. We consider that the crystalline growth posterior to the nucleation is facilitated by boron atoms existing neighbor to UNCD grains or by boron-containing energetic species in plasma.. |
| 188. | Sausan Al-Riyami, Hikaru Ichinose, and Tsuyoshi Yoshitake, Electrical Properties of n-Type Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Applicable to Photovoltaics, Technical Digest of the 21st International Photovoltaic Science and Engineering Conference, 4D-1P-10, 2011.12, Using pulsed lased deposition, an heterojunction diodes, wherein n-type 1.6 at.% nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon films were deposited on p-type silicon substrates, were electrically evaluated. The diodes exhibited a typical rectifying action with a rectification ratio of approximately three orders of magnitude at ±5 V. The large value of the estimated ideality factor in the forward voltage might be attributable to tunneling conduction. From the characteristic of the capacitance-voltage characteristics, the build-in potential was estimated to be 0.65 eV and the effective carrier density of the nitrogen-doped film was approximately 0.6–1.0×1017 cm-3.. |
| 189. | Nathaporn Promros, Kyohei Yamashita, Kenji Kawai, Ryūhei Iwasaki, Mahmoud Shaban, and Tsuyoshi Yoshitake, Photovoltaic Properties of n-type Nanocrystalline FeSi2/i-Si/p-Type Si Heterojunctions Prepared by Facing-Targets Direct-Current Sputtering, Technical Digest of the 21st International Photovoltaic Science and Engineering Conference, 3D-1P-33, 2011.12, n-type nanocrystalline (NC) FeSi2/intrinsic (i) Si/p-type Si heterojunctions fabricated by facing-target direct-current sputtering were studied. The heterojunctions exhibited a rectifying current ratio in the dark greater than three orders of magnitude at ±1 V. Their junction capacitance and leakage current were markedly reduced as compared to those p-n heterojunctions. The capacitance-voltage characteristics implied that the formation of interface states is suppressed by the i-Si insertion. From this, the photovoltaic properties were totally improved as compared to those of p-n heterojunctions.. |
| 190. | Shinya Ohmagari, Yūki Katamune, and Tsuyoshi Yoshitake, Photovoltaic Characteristics of Ultrananocrystalline Diamond/Hydrogenated Amorphous carbon Composite Films Evaluated under UV Light, Technical Digest of the 21st International Photovoltaic Science and Engineering Conference, 3D-1P-23, 2011.12, hotovoltaic properties of boron incorporated p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films have been investigated under illumination of UV light. The spectral response of the films showed a strong response at wavelengths between 210 and 280 nm, which might be originated from UNCD crystallites. The heterojunction comprised of p-type UNCD/a-C:H and n-type Si having good rectification characteristics exhibited an increase of photocurrent approximately one order of magnitude under illumination of a 254 nm UV light. The diodes showed an essentially high quantum efficiency of 71 % with large responsivity of 130 mA/W, suggesting that UNCD/a-C:H are a new promising material applicable to photovoltaic layers for UV lights.. |
| 191. | Nathaporn Promros, Kyohei Yamashita, Ryūhei Iwasaki, Shota Izumi, Mahmoud Shaban, and Tsuyoshi Yoshitake, Current transport mechanism in n-type β-FeSi2/p-type Si heterojunction photodiodes prepared by facing-targets direct-current sputtering, Proceedings of The 13th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 179-180., 2011.11, n-Type β-FeSi2/p-type Si heterojunction, wherein the β-FeSi2 films were epitaxially grown on Si(111) substrates at a substrate temperature of 600 °C by facing-targets direct-current sputtering (FTDCS) without post-annealing, were structurally and electrically investigated. Three types of epitaxial variant of β-FeSi2 were confirmed by x-ray diffraction analysis. From the atomic force microscopic observations, it was found that the β-FeSi2 layer consists of a large number of rectangular crystallites with short sides of 50-100 nm. These are attributable to the variant epitaxial growth of β-FeSi2 on Si(111). The current-voltage characteristics of the heterojunction exhibited rectifying properties accompanied by large leakage and ideality factor greater than 2. This indicated that a tunneling effect contributes to the carrier conduction in the β-FeSi2 films. Therefore, the grain boundaries in the β-FeSi2 film act as trap and tunneling leakage centers, which degrades the photodetection performance of the β-FeSi2/Si photodiodes.. |
| 192. | Kyohei Yamashita, Nathaporn Promros, Ryūhei Iwasaki, Shota Izumi, and Tsuyoshi Yoshitake, Influences of hydrogen passivation on photodetection of n-type β-FeSi2/p-type Si heterojunction photodiodes fabricated by facing-targets direct-current sputtering, Proceedings of The 13th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 175-176, 2011.11, Hydrogen passivation was applied to the initial epitaxial growth of n-type β-FeSi2 thin films on p-type Si(111) substrates by facing-targets direct-current sputtering (FTDCS) in order to reduced the formation of interface states and terminate danging bonds in the -FeSi2 films, and the passivation effects were studied on basis of the electrical evaluation results of the formed n-type β-FeSi2/p-type Si heterojunction photodiades. The initial growth was made at different gas inflow H2/Ar ratios ranging from 0 to 0.2. The photodetection performance of the photodiode fabricated at the ratio of 0.2 was markedly improved as compared to those of the other samples. The quantum efficiency and detectivity were 2.08 % and 1.75 × 1010 cm√Hz/W, respectively. The sample exhibited the minimum junction capacitance density of 9.2 nF/cm2. The enhanced photodetective performance should be mainly because dangling bonds that act as trap centers for photocarriers was effectively inactivated by the passivation.. |
| 193. | Takayuki Sonoda, Yūta Noda, Shinichi Hirakawa, Kenichiro Sakai, Kaoru Takeda, and Tsuyoshi Yoshitake, Current-induced magnetization switching in Fe3Si/FeSi2 multilayerd films, Proceedings of The 13th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 159-160, 2011.11, Fe3Si/FeSi2 multilayered films were prepared on Si(111) by facing targets direct-current sputtering, and the current-induced magnetization switching in current-perpendicular-to-plane (CPP) and current-in-plane (CIP) geometries was studied for the antiferromagnetically coupled films, respectively. The electrical resistance was alternatively changed for the injection current. Since the large and small values were in agreement with those of the antiferromagnetically and ferromagnetically coupled films, the alternative change in the electrical resistivity for the injection current should be attributed to the switching in the interlayer coupling. Under a magnetic field, the electrical resistivity was hardly changed for the injection current since the interlayer-coupling is fixed to be ferromagnetic.. |
| 194. | Hikaru Ichinose, Sausan Al-Riyami, and Tsuyoshi Yoshitake, Mechanical properties of silicon-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films, Proceedings of The 13th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 157-158, 2011.11, 7.6 at.% silicon-doped ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite (UNCD/a-C:H) films, which were prepared by pulsed laser deposition using a 10 at.% silicon-contained graphite target, exhibited dramatically enhanced hardness of 28 GPa and modulus of 245 GPa as compared to those of undoped UNCD/a-C:H films. In order to study the origins, their chemical bonding structures were examined by near-edge X-ray absorption fine-structure (NEXAFS) and X-ray photoemission spectroscopies with synchrotron radiation. The NEXAFS measurement implies that hydrogen atoms that terminate dangling bonds of UNCD grains are partially replaced with Si atoms, and the X-ray photoemission spectra indicated that sp2 C=C bonds are partially replaced with sp3 C‒Si bonds. The former and latter replacements might occur predominantly in grain boundaries and an a-C:H matrix, respectively. We consider that these replacements are the origins of the enhanced hardness and modulus, and particularly the former replacement that is specific to UNCD/a-C:H films should contribute to the dramatic enhancement.. |
| 195. | Shinya Ohmagari, Yūki Katamune, and Tsuyoshi Yoshitake, Ultrananocrystalline diamond/hydrogenated amorphous carbon composite films for photovoltaic applications, Proceedings of The 13th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 43-44, 2011.11, Photovoltaic properties of boron incorporated p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films have been investigated under illumination of UV light. The photoconduction spectrum showed a strong response at wavelengths between 210 and 280 nm, which should originate from UNCD crystallites. The heterojunction comprised of p-type UNCD/a-C:H and n-type Si exhibited an obvious photocurrent under the illumination of a 254-nm monochromatic light. The external quantum efficiency and responsivity were estimated to be 71 % and 130 mA/W, respectively. UNCD/a-C:H are a new promising material applicable to photovoltaic layers for UV lights.. |
| 196. | Mahmoud Shaban, Nathaporn Promros, Shota Izumi, and Tsuyoshi Yoshitake, Structural and electrical properties of sputtered b-FeSi2 films deposited on Si(111) substrates for photovoltaic applications, Proc. of IQCMEA-ICF-Processing, Performance and Failure Analysis of Engineering Materials (2011), pp. 442-446, 2011.11. |
| 197. | Mahmoud Shaban, Chen Li, Nathaporn Promros, and Tsuyoshi Yoshitake, Electrical properties of nanocrystalline-FeSi2 films prepared by pulsed laser deposition, Proc. of IQCMEA-ICF-Processing, Performance and Failure Analysis of Engineering Materials, pp. 437-441, 2011.11, Nanocrystalline iron disilicide (NC-FeSi2) thin films were grown on Si substrates at room temperature by pulsed-laser deposition (PLD) without post-annealing. The films were structurally investigated by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was confirmed that the films comprises crystallites with diameters ranging from 3 to 5 nm. The unintentionally doped films showed n-type conduction, which was thermally confirmed. n-Type NC-FeSi2/p-type Si heterojunctions exhibited good rectifying properties with a rectification ratio of two orders of magnitude at ±1 V. The leakage current density was less than 2 × 10–3 A/cm2, measured at –5 V and 300 K. The obtained results illustrates that NC-FeSi2 is a promising material for optoelectronic devices. . |
| 198. | Sausan Al-Riyami, Shinya Ohmagari, and Tsuyoshi Yoshitake, Erratum: “Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed Laser Deposition” [Applied Physics Express 3 (2010) 115102], Appl. Phys. Express, 10.1143/APEX.4.109201, 4 (2011) 109201., 2011.10, [URL]. |
| 199. | Shin-ichi Hirakawa, Takayuki Sonoda, Ken-ichiro Sakai, Kaoru Takeda1, and Tsuyoshi Yoshitake, Temperature-Dependent Current-Induced Magnetization Switching in Fe3Si/FeSi2/Fe3Si trilayered films, Jpn. J. Appl. Phys., 10.1143/JJAP.50.08JD06, Vol. 50, No. 8 (2011) 08JD06., 2011.08, [URL], Fe3Si/FeSi2/Fe3Si trilayered films were grown on Si(111) substrates at a substrate temperature of 300 °C by facing-targets direct-current sputtering, and current-induced magnetization switching in current-perpendicular-to-plane geometry was studied for the films wherein an antiferromagnetic interlayer coupling perpendicular to the plane was probably formed at room temperature. The appearance of a hysteresis loop in the electrical resistance–injection current curve well coincided with that of a hysteresis loop in the magnetization curve perpendicular to the plane. In addition, the hysteresis loop in the electrical resistance–injection current curve disappeared under large magnetic fields. The origin of the change in the electrical resistance for the injection current might be the change in the interlayer coupling. . |
| 200. | Sausan Al-Riyami, Shinya Ohmagari, and Tsuyoshi Yoshitake, Near-Edge X-ray Absorption Fine-Structure Spectroscopic Study on Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed Laser Deposition, Jpn. J. Appl. Phys., 10.1143/JJAP.50.08JD05, Vol. 50, No. 8 (2011) 08JD05., 2011.08, [URL], Nitrogen-doped ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite films, which possessed n-type conduction with enhanced electrical conductivity, were prepared by pulsed laser deposition. The film doped with a nitrogen content of 7.9 at. % possessed enhanced electrical conductivity of 18 Ω-1·cm-1 at 300 K. The near-edge X-ray absorption fine-structure (NEXAFS) measurement indicated the appearance of additional peaks due to π* C=N, σ* C=N, and σ* C–N bonds compared with the spectra of undoped films. The sp2 bonding fraction estimated from the NEXAFS spectra increased with the nitrogen content. The enhanced electrical conductivity is probably due to the formation of additional π* and σ* states and the enhancement in the sp2 bonding fraction. . |
| 201. | Tsuyoshi Yoshitake, Shinya Ohmagari and Sausan AL-Riyami, Ryota Ohtani, Kazushi Sumitani, Hiroyuki Setoyama, Eiichi Kobayashi, Toshihiro Okajima, and Yasuharu Hirai, Basic study on the application of ultrananocrystalline diamond/hydrogenated amorphous carbon to photodiodes, NanotechJapan Bulletin, Vol. 4, No. 4, 2011-08-24 (2011) No. 20. , 2011.07, [URL]. |
| 202. | Al-Riyami Sausan, Shinya Ohmagari, and Tsuyoshi Yoshitake, Fourier Transform Infrared Spectroscopic Study of Nitrogen-Doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed laser Deposition, Diamond Relat. Mater., Vol. 20 (2011) pp. 1072-1075., 2011.06. |
| 203. | Yoji Akaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Shigeuki Nakamura, Takahiro Tokuda, and Kenji Yoshino, Effect of H2S Annealing on Ag-Rich Ag–In–S Thin Films Prepared by Vacuum Evaporation, 10.1143/JJAP.50.05FB06, Vol. 50, No. 2 (2011) 05FB06. , 2011.05, [URL], We investigated the effect of H2S annealing on Ag–In–S thin films prepared by vacuum evaporation. In thin films annealed above 350 °C, diffraction peaks except chalcopyrite AgInS2 phase were not observed for a starting material ratio of 1.0 but observed for that of 1.2. Thin films annealed at 400 °C with a starting material ratio of 1.5 contained several phases. We found that the Ag/In ratios of the films could be controlled by changing the starting material ratio. Grains of films with composition ratios of 1.0 and 1.2 were nonuniform, whereas those with a composition ratio of 1.5 were uniform. . |
| 204. | Shin-ichi Hirakawaa, Ken-ichiro Sakaia, Takayuki Sonoda, Kaoru Takeda, and Tsuyoshi Yoshitake, Current-Induced Magnetization Switching in Fe3Si/FeSi2 Superlattices, Physics Procedia, in press, 2011.04. |
| 205. | Shinya Ohmagari, Sausan Al-Riyami, and Tsuyoshi Yoshitake, p-Type ultrananocrystalline diamond/hydrogenated amorphous carbon composite/n-type Si heterojunction diodes fabricated by pulsed laser deposition, Jpn. J. Appl. Phys. , 10.1143/JJAP.49.031302, Vol. 50, No. 3, 035101., 2011.03, [URL], p-Type ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) composite films were fabricated by pulsed laser deposition using boron-doped graphite targets. Thermal analysis confirmed the occurrence of p-type conduction. The electrical conductivity increased with the doped amount of boron. An activation energy estimated from the Arrhenius plot was approximately 0.1 eV. Near-edge X-ray absorption fine structure spectra revealed that the σ*C–H peak weakened and the σ*C–B peak strengthened with an increase in the doped amount of boron. Fourier transform infrared spectroscopy showed that the sp3 C–H peak weakened with the doped amount of boron. These probably indicate that the hydrogen atoms that terminate the dangling bonds of UNCD crystallites are partially replaced with boron atoms. . |
| 206. | Kenji Hanada, Tomohiro Yoshida, You Nakagawa, and Tsuyoshi Yoshitake, Formation of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films in Vacuum by Using A Coaxial Arc Plasma Gun, Jpn. J. Appl. Phys., 10.1143/JJAP.49.125503, Vol. 49, No. 12 (2010) 125503., 2010.12, [URL], Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite films were grown in vacuum using a coaxial arc plasma gun. From the X-ray diffraction measurement, the UNCD crystallite size was estimated to be 1.6 nm. This size is dramatically reduced from that (2.3 nm) of UNCD/hydrogenated amorphous carbon (a-C:H) composite films grown in a hydrogen atmosphere. The sp3/(sp3 + sp2) value, which was estimated from the X-ray photoemission spectrum, was also reduced to be 41%. A reason for it might be the reduction in the UNCD crystallite size. From the near-edge X-ray absorption fine-structure (NEXAFS) spectrum, it was found that the π*C=C and π*C≡C bonds are preferentially formed instead of the σ*C–H bonds in the UNCD/a-C:H films. Since the extremely small UNCD crystallites (1.6 nm) correspond to the nuclei of diamond, we consider that UNCD crystallite formation should be due predominantly to nucleation. The supersaturated condition required for nucleation is expected to be realized in the deposition using the coaxial arc plasma gun. . |
| 207. | Mahmoud Shaban, Kenji Kawai, Nathaporn Promros, and Tsuyoshi Yoshitake, n-Type Nanocrystalline-FeSi2/p-Type Si Heterojunction Photodiodes Prepared at Room Temperature, IEEE Electron Device Lett., Vol. 31, No. 12, pp. 1428-1430., 2010.12. |
| 208. | Sausan Al-Riyami, Shinya Ohmagari, and Tsuyoshi Yoshitake, Electrical Properties and Chemical Bonding Structures of Nitrogen-doped Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed Laser Deposition, Appl. Phys. Express, 10.1143/APEX.3.115102, Vol. 3, No. 11 (2010) 115102., 2010.11, [URL], Nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films were deposited by pulsed laser deposition. The film doped with a nitrogen content of 7.9 at.% possessed n-type conduction with an electrical conductivity of 181cm1 at 300 K. A heterojunction with p-type Si exhibited typical rectifying action. The UNCD grain size was estimated to be 2.5nm from X-ray diffraction measurement. Near-edge X-ray absorption fine-structure and Fourier transform infrared spectroscopies revealed the preferential formations of C¼N and C–N bonds and an enhanced amount of sp2 bonds in the films.. |
| 209. | Sausan Al-Riyami, Shinya Ohmagari, and Tsuyoshi Yoshitake, Nitrogen Doped-Ultrananocrystalline diamond /hydrogena ted amorphous carbon composite films prepared by pulsed laser deposition, Proceedings of The 12th Cross Straits Symposium on Materials, Energy and Environment Sciences, (2010) pp. 94-95., 2010.11. |
| 210. | Chen Li, Wataru Yokoyama, Shota Izumi, Promros Nathaporn, and Tsuyoshi Yoshitake, Fabrication of n-type β-FeSi2/p-type Si heterojunctions by pulsed laser deposition and their application to NIR photodiodes, Proceedings of 2010 IEEE Region 10 Conference, pp. 2225-2227., 2010.11. |
| 211. | Tomohiro Yoshida, Kenji Hanada, You Nakagawa, Ryota Ohtani, Kazushi Sumitani, Hiroyuki Setoyama, Eiichi Kobayashi, Yoshiaki Agawa, and Tsuyoshi Yoshitake, Influences of Arc Discharge Repetition Rate on Growth of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films by A Coaxial Arc Plasma Gun, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) KWP-076(2pages), 2010.10. |
| 212. | Kenji Hanada, Tomohiro Yoshida, You Nakagawa, Ryota Ohtani, Kazushi Sumitani, Hiroyuki Setoyama, Eiichi Kobayashi, and Tsuyoshi Yoshitake, Formation of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films in Vacuum by Using A Coaxial Arc Plasma Gun, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) KWP-075(2pages), 2010.10. |
| 213. | Shota Izumi, Nathaporn Promros, Mahmoud Shaban, Keita Nomoto, and Tsuyoshi Yoshitake, n-type β-FeSi2 / p-type Si Heterojunction Photodiodes Fabricated by Facing Targets Direct-Current Sputtering, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) KWP-074(2pages), 2010.10. |
| 214. | Shin-ichi Hirakawa, Ken-ichiro Sakai, Kaoru Takeda, and Tsuyoshi Yoshitake, Fabrication of Fe3Si/FeSi2 Multilayers by Facing Targets Direct-Current Sputtering and The Magnetic Properties, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) KWP-073(2pages), 2010.10. |
| 215. | Nathaporn Promros, Chen Li, Wataru Yokoyama, and Tsuyoshi Yoshitake, Preparation of n-Type β-FeSi2/p-Type Si Heterojunctions for Near-Infrared Photodetectors by Pulsed Laser Deposition, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-046(2pages), 2010.10. |
| 216. | Shinya Ohmagari, Kenji Hanada, Akira Nagano, Ryota Ohtani, Kazushi Sumitani, and Tsuyoshi Yoshitake, Influences of Boron-Doping on Growth of Ultrananocrystalline Diamond⋅Hydrogenated Amorphous Carbon Composite Films by Pulsed Laser Deposition, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-047(2pages), 2010.10. |
| 217. | Sausan Al-Riyami, Shinya Ohmagari, and Tsuyoshi Yoshitake, Incorporation Effects of Nitrogen into Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films by Physical Vapor Deposition, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) CTP-185(2pages), 2010.10. |
| 218. | Shin-ichi Hirakawa, Ken-ichiro Sakai, Kaoru Takeda, and Tsuyoshi Yoshitake, Temperature-Dependent Interlayer Couplings in Fe3Si/FeSi2 multilayers prepared by facing targets direct-current sputtering, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) CTP-187(2pages), 2010.10. |
| 219. | Kazushi Sumitani, Ryota Ohtani, Tomohiro Yoshida, Satoshi Mohri, Tsuyoshi Yoshitake, Crystallographic Study of Cubic Phase AlN Thin Films Heteroepitaxially Grown on Sapphire(0001) Substrates by Pulsed Laser Deposition, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-044(2pages), 2010.10. |
| 220. | Nathaporn Promros, Kenji Kawai, Mahmoud Shaban, and Tsuyoshi Yoshitake, Characteristics of Near-Infrared n-Type Nanocrystalline FeSi2/i-Si/p-Type Si Heterojunctions prepared by Facing-Targets Direct Current Sputtering, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-033(2pages), 2010.10. |
| 221. | Kazushi Sumitani, Ryota Ohtani, Eisuke Magome, Tomohiro Yoshida, Satoshi Mohri, Tsuyoshi Yoshitake, Effects of Ambient Nitrogen on Growth of Cubic AlN Films on Sapphire(0001) Substrates by Pulsed Laser Deposition, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-045(2pages), 2010.10. |
| 222. | Tomohiro Yoshida, Kazushi Sumitani, Ryota Ohtani, Satoshi Mohri, and Tsuyoshi Yoshitake, Influences of Repetition Rate of Laser Pulses on Growth of AlN Thin Films on Sapphire(0001) by Reactive Pulsed Laser Deposition, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-040(2pages), 2010.10. |
| 223. | Shota Izumi, Nathaporn Promros, Mahmoud Shaban, Keita Nomoto, and Tsuyoshi Yoshitake, Formation of n-Type β-FeSi2/p-Type Si Heterojunctions by Facing-Targets Direct-Current Sputtering, Proceedings of 63rd Annual Gaseous Electronics Conference and 7th International Conference on Reactive Plasmas, (2010) DTP-042(2pages), 2010.10. |
| 224. | Nathaporn Promros, Kenji Kawai, Kyohei Yamashita, Mahmoud Shaban, and Tsuyoshi Yoshitake, Applications of n-Type Nanocrystalline FeSi2/i-Si/p-Type Si Heterojunctions Prepared by Facing-Targets Direct-Current Sputtering to Photovoltaics, Proceeding of The 3rd Regional Conference Interdisciplinary Research on Natural Resources and Materials Engineering, (2010) pp. 296-299., 2010.10. |
| 225. | Nathaporn Promros, Shota Izumi, Kyohei Yamashita, Mahmoud Shaban, and Tsuyoshi Yoshitake, Formation of n-Type β-FeSi2/Intrinsic-Si/p-Type Si Heterojunctions by Facing-Targets Direct-Current Sputtering and Their Photovoltaic Properties , Proceeding of The 3rd Regional Conference Interdisciplinary Research on Natural Resources and Materials Engineering, (2010) pp. 153-157., 2010.10. |
| 226. | Kenji Hanada, Tsuyoshi Yoshitake, Takashi Nishiyama, and Kunihito Nagayama, Time-Resolved Spectroscopic Observation of Deposition Processes of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films by Using a Coaxial Arc Plasma Gun, Jpn. J. Appl. Phys., 10.1143/JJAP.49.08JF09, Vol. 49, No. 8 (2010) 08JF09., 2010.08, [URL]. |
| 227. | Yoji Akaki, Kyohei Yamashita, Tsuyoshi Yoshitake, Shigeyuki Nakamura, Satoru Seto, Takahiro Tokuda and Kenji Yoshino , Effect of annealing for Ag-In-S thin films prepared by a vacuum evaporation method, Proc. of The 35th IEEE Photovoltaic Specialists Conference, (2010) pp. 2406-2409., 2010.06. |
| 228. | Kenji Hanada, Takashi Nishiyama, Tsuyoshi Yoshitake, and Kunihito Nagayama, Optical Emission Spectroscopic of Deposition Process of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films by Using a Coaxial Arc Plasma Gun, Diamond Relat. Mater., in press, 2010.05. |
| 229. | Kazushi Sumitani, Ryota Ohtani, Tomohiro Yoshida, You Nakagawa, Satoshi Mohri, Tsuyoshi Yoshitake, Influences of repetition rate of laser pulses on growth of crystalline AlN films on sapphire(0001) substrates by pulsed laser deposition, Diamond Relat. Mater., Vol. 19 (2010) pp. 618-620., 2010.04. |
| 230. | Sausan Al-Riyami, Shinya Ohmagari, and Tsuyoshi Yoshitake, X-ray Photoemission Spectroscopy of Nitrogen-Doped UNCD /a-C:H Films Prepared by Pulse Laser Deposition, Diamond Relat. Mater., 10.1016/j.diamond.2010.01.023, Vol. 19 (2010) pp. 510-513., 2010.04. |
| 231. | Shinya Ohmagari, Tsuyoshi Yoshitake, Akira Nagano, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, and Kunihito Nagayama, X-ray photoemission spectroscopy study of ultrananocrystalline diamond/hydrogenated amorphous carbon films prepared by pulsed laser deposition, Diamond Relat. Mater., in press, 2010.04. |
| 232. | Shinya Ohmagari, Tsuyoshi Yoshitake , Akira Nagano, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, Takeshi Hara, and Kunihito Nagayama, Formation of p-Type Semiconducting Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films by Boron Doping, Jpn. J. Appl. Phys., 10.1143/JJAP.49.031302, Vol. 49, No. 3 (2010) 031302, 2010.03, [URL]. |
| 233. | Kazushi Sumitani , Ryota Ohtani, Tomohiro Yoshida, You Nakagawa, Satoshi Mohri, and Tsuyoshi Yoshitake, Synchrotron X-ray Diffraction Study of Single-Phase β-AlN Thin Film Heteroepitaxially Grown on a Sapphire(0001) Substrate by Pulsed Laser Deposition, Jpn. J. Appl. Phys. , Vol. 49, No. 2 (2010) 020212., 2010.02. |
| 234. | Tsuyoshi Yoshitake, You Nakagawa, Akira Nagano, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, Kazushi Sumitani, Yoshiaki Agawa, and Kunihito Nagayama, Structural and physical characteristics of ultrananocrystalline diamond/hydrogenated amorphous carbon composite films deposited using a coaxial arc-plasma gun, Jpn. J. Appl. Phys., 10.1143/JJAP.49.015503, Vol. 49, No. 1, 015503, 2010.01, [URL]. |
| 235. | Kenji Hanada, Takashi Nishiyama, Tsuyoshi Yoshitake, Kunihito Nagayama, Roles of hydrogen atmospheres in growth of ultrananocrystalline diamond by pulsed laser deposition, Mater. Sci. Forum, 638-642, pp. 1685-1690, 2010.01. |
| 236. | You Nakagawa, Tsuyoshi Yoshitake, Kenji Hanada, Akira Nagano, Ryota Ohtani, Kazushi Sumitani, Hiroyuki Setoyama, Eiichi Kobayashi, Masaaki Hirakawa, Koichi Yamaguchi, Naoki Tsukahara, Yoshiaki Agawa, Kunihito Nagayama, Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Films Prepared by a Coaxial Arc Plasma Gun, Mater. Sci. Forum, 638-642. pp. 2927-2932, 2010.01. |
| 237. | Tomohiro Yoshida, Tsuyoshi Yoshitake, Kazushi Sumitani, Ryota Ohtani, You Nakagawa, Satoshi Mohri, Kunihito Nagayama, Growth of Cubic AlN Films on Sapphire(0001) with Atomic Scale Surface Smoothness by Pulsed Laser Deposition, Mater. Sci. Forum, 638-642, pp. 2921-2926, 2010.01. |
| 238. | Tsuyoshi Yoshitake, Akira Nagano, Shinya Ohmagari, Masaru Itakura, Noriyuki Kuwano, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, and Kunihito Nagayama, Erratum: “Near-Edge X-ray Absorption Fine-Structure, X-ray Photoemission, and Fourier Transform Infrared Spectroscopies of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films”[Jpn. J. Appl. Phys. 48 (2009) 020222], Jpn. J. Appl. Phys., Vol. 49, No. 1, 019201, 2010.01. |
| 239. | Kenji Kawai, Mahmoud Shaban, Haruhiko Kondo, and Tsuyoshi Yoshitake, Characterizations of near-infrared n-type nanocrystalline-FeSi2/p-type Si heterojunction photodiodes at low temperatures, Proceedings of The 11th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 145-146, 2009.11. |
| 240. | K. Sakai, S. Hirakawa, K. Takeda, and T. Yoshitake, Current-induced magnetization switching in Fe3Si/FeSi2/Fe3Si trilayer films, Proceedings of The 11th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 165-166, 2009.11. |
| 241. | Sausan Al-Riyami, Tsuyoshi Yoshitake, Shinya Ohmagari, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, and Kunihito Nagayama, X-RAY PHOTOEMISSION SPECTROSCOPY OF NITROGEN-DOPED UNCD/a-C:H FILMS PREPEARED BY PULSE LASER DEPOSITION, Proceedings of The Third International Symposium on Novel Carbon Resource Sciences: Advanced Materials, Processes and Systems toward CO2 Mitigation, pp. 387-392., 2009.11. |
| 242. | Shinya Ohmagari, Tsuyoshi Yoshitake, Akira Nagano, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, and Kunihito Nagayama, Chemical bonding configuration and electrical property of boron-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films, Proceedings of The Third International Symposium on Novel Carbon Resource Sciences: Advanced Materials, Processes and Systems toward CO2 Mitigation, pp. 393-398., 2009.11. |
| 243. | Mahmoud Shaban, Shota Izumi, Keita Nomoto, and Tsuyoshi Yoshitake, "n-Type β-FeSi2/intrinsic-Si/p-type Si heterojunction photodiodes for near-infrared light detection at room temperature", Appl. Phys. Lett., 10.1063/1.3250171 , Vol.95 (2009) 162102., 2009.10, [URL]. |
| 244. | Mahmoud Shaban, Keita Nomoto, Shota Izumi, and Tsuyoshi Yoshitake, "Characterization of near-infrared n-type β-FeSi2/p-type Si heterojunction photodiodes at room temperature", Appl. Phys. Lett., 10.1063/1.3151915 , 94 (2009) 222113., 2009.06, [URL]. |
| 245. | Keita Nomoto, Mahmoud Shaban, Haruhiko Kondo, and Tsuyoshi Yoshitake, "Photovoltaic Properties of n-Type Nanocrystalline-FeSi2/Intrinsic-Si/p-Type Si Heterojunctions Fabricated by Facing-Targets DC Sputtering", IEEE Proceedings of 2008 Conference on Optoelectronic and Microelectronic Materials and Devices (COMMAD '08), pp. 263-266 (2008)., 2009.04. |
| 246. | Shinya Ohmagari, Tsuyoshi Yoshitake, Akira Nagano, Sausan AL-Riyama, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi and Kunihito Nagayama, "Near-edge X-ray absorption fine-structure of ultrananocrystalline diamond/amorphous carbon films prepared by pulsed laser deposition", J. Nanomater., in press, 2009.03. |
| 247. | Tsuyoshi YOSHITAKE , Akira NAGANO, Shinya OHMAGARI, Masaru ITAKURA, Noriyuki KUWANO, Ryota OHTANI, Hiroyuki SETOYAMA, Eiichi KOBAYASHI, and Kunihito NAGAYAMA, "Near-edge X-ray absorption fine-structure, X-ray photoemission, Fourier transfer infrared spectroscopies of ultrananocrystalline diamond/hydrogenated amorphous carbon composite films" , Jpn. J. Appl. Phys., 10.1143/JJAP.48.020222, Vol. 48, No. 2 (2009) 020222., 2009.02, [URL]. |
| 248. | Kaoru TAKEDA, Tsuyoshi YOSHITAKE, Yoshiki SAKAMOTO, Daisuke HARA, Masaru ITAKURA, Noriyuki KUWANO, and Kunihito NAGAYAMA, "Interfacial structure of Fe3Si/FeSi2 layered films deposited on Si (111) at elevated substrate-temperatures", Int. J. Mod. Phys., to be published, 2009.02. |
| 249. | Kenji Hanada, Takashi Nishiyama, Tsuyoshi Yoshitake, and Kunihito Nagayama, "Time-resolved Observation of Deposition Process of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films in Pulsed Laser Deposition", J. Nanomater., 2009 (2009) 901241., 2009.01. |
| 250. | K. Nomoto, M. Shaban, and T. Yoshitake, "EFFECTS OF INTRINSIC Si EMISSION LAYERS INSERTED IN N-TYPE -FeSi2/P-TYPE Si HETEROJUNCTIONS ON RECTIFICATION AND PHOTOVOLTAIC PROPERTIES", Proceedings of the 10th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 149-149, 2008.11. |
| 251. | K. Hanada, T. Nishiyama, T. Yoshitake, and K. Nagayama, "CONSIDERATION OF DEPOSITION PROCESS OF ULTRANANOCRYSTALLINE DIAMOND THIN FILMS BY PULSED LASER DEPOSITION" , Proceeding of the 10th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 134-135., 2008.11. |
| 252. | M. Shaban, K. Kawai, H. Kondo, T. Yoshitake, "NANOCRYSTALLINE-FeSi2/INTRINSIC AMORPHOUS-Si/Si HETEROJUNCTIONS FOR PHOTOVOLTAIC APPLICATION" , Proceeding of the 10th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 146-147., 2008.11. |
| 253. | You Nakagawa, Kenji Hanada, Akira Nagano, and Tsuyoshi Yoshitake, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, Kazushi Sumitani, and Toshihiro Okajima, Masaaki Hirakawa, Koichi Yamaguchi, and Naoki Tsukahara, Yoshiaki Agawa, and Kunihito Nagayama, "ULTRANANOCRYSTALLINE DIAMOND/HYDROGENATED AMORPHOUS CARBON COMPOSITE FILMS PREPARED BY A COAXIAL ARC PLASMA GUN", Proceeding of the 10th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 136-137., 2008.11. |
| 254. | Shinya Ohmagari, Akira Nagano, Tsuyoshi Yoshitake, Ryota Ohtani, Hiroyuki Setoyama, Eiichi Kobayashi, and Kunihito Nagayama, "Near-edge X-ray absorption fine structure of Ultrananocrystalline diamond/hydrogenated amorphous carbon composite films", Proceeding of the 10th Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 138-139., 2008.11. |
| 255. | Nilesh. J. Vasa, Yasunari Hata, Tsuyoshi Yoshitake, Shigeru Yokoyama, Preparation of KTiOPO4 thin films on different substrates by pulsed laser deposition, Int. J. Adv. Manuf. Technol, 38, pp. 600-604., 2008.09. |
| 256. | Satoshi MOHRI, Tsuyoshi YOSHITAKE, Takeshi HARA, and Kunihito NAGAYAMA, "Growth of metastable cubic AlN by reactive pulsed laser deposition", Diamond Rel. Mater., 17, pp. 1796-1799, 2008.08. |
| 257. | Mahmoud SHABAN, Haruhiko KONDO, Kazuhiro NAKASHIMA, and Tsuyoshi YOSHITAKE, "Electrical and Photovoltaic Properties of n-Type Nanocrystalline FeSi2/p-Type Si Heterojunctions Prepared by Facing Target Direct-current Sputtering at Room Temperature", Jpn. J. Appl. Phys, 10.1143/JJAP.47.5420, Vol. 47, No. 7, pp. 5420-5422., 2008.07, [URL]. |
| 258. | Mahmoud SHABAN, Keita NOMOTO, Kazuhiro NAKASHIMA, and Tsuyoshi YOSHITAKE, "Low-temperature Annealing of n-type β-FeSi2/p-type Si Heterojunctions" , Jpn. J. Appl. Phys, Vol. 47, No. 5, pp. 3444-3446., 2008.05. |
| 259. | Tsuyoshi YOSHITAKE , Satoshi MOHRI, Takeshi HARA, and Kunihito NAGAYAMA, "Growth of metastable β-AlN by pulsed laser deposition", Jpn. J. Appl. Phys, Vol. 47, No. 5, pp. 3600-3602, 2008.05. |
| 260. | Kenji Yoshino, Aya Kinoshita, Yasuhiro Shirahata, Minoru Oshita, Keita Nomoto, Tsuyoshi Yoshitake, and Tetsuo Ikari, "Structural and electrical characterization of AgInSe2 crystals grown by hot-press method", J. Phys: Conf. Series, 100 (2008) 042042, 2008.04. |
| 261. | Y. Akaki, K. Nomoto, S. Nakamura, T. Yoshitake, and K. Yoshino, "Effect of H2S annealing for CuInS2 thin films prepared by a vacuum evaporation method", J. Phys: Conf. Series, 100 (2008) 082022, 2008.04. |
| 262. | K. Yoshino, K. Nomoto, A. Kinoshita, T. Ikari, Y. Akaki, and T. Yoshitake, "Dependence of Cu/In ratio of structural and electrical characterization of CuInS2 crystal", J. Mater. Sci.: Mater. Electron., Vol. 19, pp. 301-304., 2008.02. |
| 263. | Kaoru TAKEDA, Tsuyoshi YOSHITAKE , Yoshiki SAKAMOTO, Tetsuya OGAWA, Daisuke HARA, Masaru ITAKURA, Noriyuki KUWANO, Toshinori KAJIWARA, and Kunihito NAGAYAMA, "Enhanced interlayer coupling and magnetoresistance ratio in Fe3Si/FeSi2 superlattices", Appl. Phys. Express, Vol. 1, No. 2 (2008) 021302., 2008.02. |
| 264. | Mahmoud SHABAN, Kazuhiro NAKASHIMA, and Tsuyoshi YOSHITAKE, "Substrate Temperature Dependence of Photovoltaic Properties of β-FeSi2/Si Heterojunctions Prepared by Facing-target DC Sputtering" , Jpn. J. Appl. Phys. Part 1, Vol. 46, No. 12, pp. 77087710, 2007.12. |
| 265. | Kaoru TAKEDA, Tsuyoshi YOSHITAKE, Dai NAKAGAUCHI, Tetsuya OGAWA, Daisuke HARA, Masaru ITAKURA, Noriyuki KUWANO, Yoshitsugu TOMOKIYO, Toshiyuki KAJIWARA, and Kunihito Nagayama, "Epitaxy in Fe3Si/FeSi2 superlattices prepared by facing target direct-current sputtering at room tempertaure", Jpn. J. Appl. Phys. Part 1, Vol. 46, No. 12, pp. 78467848., 2007.12. |
| 266. | Mahmoud Shaban, Kazuhiro Nakashima, Keita Nomoto, Tsuyoshi Yoshitake, "N-TYPE β-FeSi2/P-TYPE Si HETEROJUNCTION SOLAR CELL FABRICATED BY FACING-TARGET DC SPUTTERING", Technical Digest of the 17th International Photovoltaic Science and Engineering Conference (PVSEC-17), 6P-P5-36, 2007.12. |
| 267. | Keita NOMOTO, Mahmoud SHABAN, Kazuhiro NAKASHIMA and Tsuyoshi YOSHITAKE, "THERMAL POST-ANNEALING EFFECT ON PHOTOVOLTAIC PROPERTIES OF n-TYPE β-FeSi2/p-TYPE Si HETEROJUNCTION", Technical Digest of the 17th International Photovoltaic Science and Engineering Conference (PVSEC-17), 6P-P5-60, 2007.12. |
| 268. | Haruhiko KONDO, Mahmoud SHABAN, Kazuhiro NAKASHIMA, Tsuyoshi YOSHITAKE, "SYNTHESIS OF NANOCRYSTALLINE FeSi2 /Si HETEROJUNCTIONS FOR PHOTOVOLTAIC APPLICATIONS BY FACING-TARGET DC SPUTTERING", Technical Digest of the 17th International Photovoltaic Science and Engineering Conference (PVSEC-17), 6P-P5-73, 2007.12. |
| 269. | Y. Akaki, K. Nomoto, S. Nakamura, T. Yoshitake, K. Yoshino, "CHARACTERIZATION OF EVAPORATED CUINS2 FILMS ANNEALED IN HYDROGEN SULFIDE ATMOSPHERE", Technical Digest of the 17th International Photovoltaic Science and Engineering Conference (PVSEC-17), 5P-P3-03, 2007.12. |
| 270. | Tsuyoshi YOSHITAKE, Akira NAGANO, Masaru ITAKURA, Noriyuki KUWANO, Takeshi HARA, and Kunihito NAGAYAMA, "Spectral absorption properties of ultrananocrystalline diamond/amorphous carbon composite thin films prepared by pulsed laser deposition", Jpn. J. Appl. Phys. Part 2, 10.1143/JJAP.46.L936, Vol.46, No.38, pp.L936 - L938, 2007.10, [URL]. |
| 271. | Mahmoud SHABAN, Kazuhiro NAKASHIMA, Wataru YOKOYAMA, and Tsuyoshi YOSHITAKE, "Photovoltaic Properties of n-type β-FeSi2/p-type Si Heterojunctions", Jpn. J. Appl. Phys. Part2, 10.1143/JJAP.46.L667, Vol. 46, No.27, pp. L667-L669, 2007.07, [URL]. |
| 272. | Tsuyoshi YOSHITAKE, Kaoru TAKEDA, Dai NAKAGAUCHI, Tetsuya OGAWA, Daisuke HARA, Masaru ITAKURA, Noriyuki KUWANO, Yoshitsugu TOMOKIYO, Toshiyuki KAJIWARA, and Kunihito NAGAYAMA, "Epitaxy in Fe3Si/FeSi2 superlattices", 応用物理学会シリサイド系半導体研究会夏の学校テキスト, pp. 8-11, 2007.07. |
| 273. | T. Yoshitake, T. Ogawa, D. Nakagauchi, D. Hara, M. Itakura, N. Kuwano, Y. Tomokiyo, K. Takeda, T. Kajiwara, M. Ohashi, G. Oomi and K. Nagayama, Erratum:"Interlayer coupling in ferromagnetic epitaxial Fe3Si/FeSi2 superlattices” [Appl. Phys. Lett. 89, 253110 2006] , Appl. Phys. Lett., 90, 129901, 2007.02. |
| 274. | T. Yoshitake, T. Ogawa, D. Nakagauchi, D. Hara, M. Itakura, N. Kuwano, Y. Tomokiyo, K. Takeda, T. Kajiwara, M. Ohashi, G. Oomi and K. Nagayama, "Interlayer coupling in ferromagnetic epitaxial Fe3Si/FeSi2 superlattices", Appl. Phys. Lett., 10.1063/1.2410222 , 89, 253110, 2006.12, [URL]. |
| 275. | H. KONDO, T. YOSHITAKE, W. YOKOYAMA, M. SHABAN, K. NAKASHIMA, M. ITAKURA and N. KUWANO, and K. NAGAYAMA, "OPTICAL AND ELECTRIC PROPERTIES OF SEMICONDUCTING beta-FESI2 THIN FILMS EPITAXIALLY GROWN BY PULSED LASER DEPOSITION", Proc. of The 8th Cross Straits Symposium on Materials, Energy and Environment Sciences, P. 143-144, 2006.11. |
| 276. | M. SHABAN, K. NAKASHIMA, H. KONDO, and T. YOSHITAKE, "FABRICATION OF N-TYPE β-FeSi2 / P-TYPE Si HETEROJUNCTION SOLAR CELL", Proc. of The 8th Cross Straits Symposium on Materials, Energy and Environment Sciences, P. 147-148, 2006.11. |
| 277. | Akira NAGANO, Tsuyoshi YOSHITAKE, Masaru ITAKURA, and Noriyuki KUWANO, Takeshi HARA, and Kunihito NAGAYAMA, "OPTICAL AND ELECTRIC PROPERTIES OF ULTRANANOCRYSTALLINE DIAMOND THIN FILMS PREPARED BY PULSED LASER DEPOSITION", Proc. of The 8th Cross Straits Symposium on Materials, Energy and Environment Sciences, P. 63-64, 2006.11. |
| 278. | T. Yoshitake, Y. Inokuchi, A. Yuri, and K. Nagayama, "Direct epitaxial growth of semiconducting beta-FeSi2 thin films by facing targets direct-current sputtering", Appl. Phys. Lett., 10.1063/1.2200153 , 88, 182104, 2006.06, [URL]. |
| 279. | Takeshi Hara, Tsuyoshi Yoshitake, Tomohito Fukugawa, Hironori Kubo, Masaru Itakura, Noriyuki Kuwano, Yoshitsugu Tomokiyo and Kunihito Nagayama, "Ultrananocrystalline diamond prepared by pulsed laser deposition", Diamond and Rel. Mater., Volume 15, Issues 4-8, April-August 2006, Pages 649-653, 2006.06. |
| 280. | Tsuyoshi Yoshitake, Takeshi, Hara, Tomohito Fukugawa, Hironori Kubo, Masaru Itakura, Noriyuki Kuwano, Yoshitsugu Tomokiyo and Kunihito Nagayama, "Growth of ultrananocrystalline diamond by pulsed laser deposition", Research Signpost:Recent Developments in Lasers and their Applications, pp. 99-111, 2006.03. |
| 281. | K. Takarabe, H. Doi, Y. Mori, K. Fukui, T. Yoshitake, K. Nagayama, "Enhanced optical absorption in nano crystalline FeSi2 and hydrogenation effect on its characteristic energy", Appl. Phys. Lett., 88, 061911, 2006.02. |
| 282. | T. Yoshitake, D. Nakagauchi, T. Ogawa, M. Itakura, N. Kuwano, Y. Tomokiyo, T. Kajiwara, and K. Nagayama, "Room-temperature epitaxial growth of ferromagnetic Fe3Si films on Si(111) by facing target direct-current sputtering", Appl. Phys. Lett., 10.1063/1.1978984, 86, 26, 86, 262505, 2005.09. |
| 283. | Tsuyoshi Yoshitake, Takeshi Hara, Tomohito Fukugawa, Ling yun Zhu, Masaru Itakura, Noriyuki Kuwano, Yoshitsugu Tomokiyo and Kunihito Nagayama, "Low-Temperature Growth of Nanocrystalline Diamond by Reactive Pulsed Laser Deposition under a Hydrogen Atmosphere", Jpn. J. Appl. Phys. Part2, 10.1143/JJAP.43.L240, 43, 2B, L240-L242, Vol. 43, pp. L 240–L 242, 2004.06. |
| 284. | Taizoh Sadoh, Masakazu Owatari, Yuji Murakami, Atsushi Kenjo, Tsuyoshi Yoshitake1, Masaru Itakura and Masanobu Miyao, Formation of β-FeSi2-xGex by Ge-Segregation-Controlled Solid-Phase Growth of [a-Si/a-FeSiGe]n Multilayered Structure, Jpn. J. Appl. Phys., 10.1143/JJAP.43.1879, 43, 4B, 1879-1881, Vol. 43, No. 4B, 2004, pp. 1879-1881, 2004.01. |
| 285. | D. Nakagauchi, T. Yoshitake and K. Nagayama, Fabrication of ferromagnetic Fe3Si thin films by pulsed laser deposition using an Fe3Si target, Vacuum, 10.1016/j.vacuum.2004.01.065, 74, 3-4, 653-657, 74, 653–657, 2004.01. |
| 286. | T. Yoshitake and K. Nagayama, The velocity distribution of droplets ejected from Fe and Si targets by pulsed laser ablation in a vacuum and their elimination using a vane-type velocity filter, Vacuum, 10.1016/j.vacuum.2004.01.051, 74, 3-4, 515-520, 74, 515–520, 2004.01. |
| 287. | Takeshi Hara, Tsuyoshi Yoshitake, Tomohito Fukugawa, Ling yun Zhu, Masaru Itakura, Noriyuki Kuwano, Yoshitsugu Tomokiyo and Kunihito Nagayama, Consideration of diamond film growth on various orientation substrates of diamond in an oxygen and a hydrogen atmospheres by reactive pulsed laser deposition, Diamond Rel. Mater., 10.1016/j.diamond.2003.10.078, 13, 4-8, 622-626, 13, 622–626, 2004.01. |
| 288. | Takeshi Hara, Tsuyoshi Yoshitake, Tomohito Fukugawa, Ling yun Zhu, Masaru Itakura, Noriyuki Kuwano, Yoshitsugu Tomokiyo and Kunihito Nagayama, Nanocrystalline diamond film prepared by pulsed laser deposition in a hydrogen atmosphere, Diamond Rel. Mater., 10.1016/j.diamond.2003.10.055, 13, 4-8, 679-683, 13, 679–683, 2004.01. |
| 289. | Dai Nakagauchi, Tsuyoshi Yoshitake and Kunihito Nagayama, Fabrication of ferromagnetic Fe3Si / semiconducting nanocrystalline FeSi2 multi-layered film by a facing targets DC sputtering method, Proceedings of The 5th Cross Straits Symposium on Materials, Energy and Environment Sciences, 2003.11. |
| 290. | Tomohito FUKUGAWA, Takeshi HARA, Tsuyoshi YOSHITAKE, Ling yun Zhu, Masaru ITAKURA,, Consideration of diamond growth on various orientation substrates in ambient oxygen and hydrogen by pulsed laser deposition, Proceedings of The 5th Cross Straits Symposium on Materials, Energy and Environment Sciences, 2003.11. |
| 291. | Yosuke INOKUCHI, Tsuyoshi YOSHITAKE, Taizo SADOH, Masanobu MIYAO, and Kunihito NAGAYAMA, Optical and electrical properties of b-FeSi2 thin films grown on Si by a facing target DC sputtering method, Proceedings of The 5th Cross Straits Symposium on Materials, Energy and Environment Sciences, 2003.11. |
| 292. | Wataru Yokoyama, Tsuyoshi Yoshitake and Kunihito Nagayama, Epitaxial as-growth of beta-FeSi2 thin film on Si(111) by pulsed laser deposition, Proceedings of The 5th Cross Straits Symposium on Materials, Energy and Environment Sciences, 2003.11. |
| 293. | Ichiro TANAKA, Tsuyoshi YOSHITAKE, Shigeto OKADA, Jun-ichi YAMAKI and Kunihito NAGAYAMA, Epitaxial growth of LiCoO2 thin films on sapphire substrates, Proceedings of The 5th Cross Straits Symposium on Materials, Energy and Environment Sciences, 2003.10. |
| 294. | T. Yoshitake, M. Yatabe, M. Itakura, N. Kuwano, Y. Tomokiyo, and K. Nagayama, "Semiconducting nanocrystalline iron disilicide thin films prepared by pulsed-laser ablation", Appl. Phys. Lett., 10.1063/1.1617374, 83, 15, 3057-3059, Vol. 83, 3057-3059., 2003.10. |
| 295. | Y. Murakami, I. Tsunoda, H. Kido, A. Kenjo, T. Sadoh, M. Miyao and T. Yoshitake, Enhanced solid-phase growth of β-FeSi2 bypre-amorphization, Nuclear Instrument and Methods in Physics Research B, 10.1016/S0168-583X(03)00750-X, 206, 304-307, 206, 304-307., 2003.09. |
| 296. | Tsuyoshi Yoshitake, Dai Nakagauchi, and Kunihito Nagayama, Ferromagnetic Ironsilicide Thin Films Prepared by Pulsed Laser Deposition, Jpn. J. Appl. Phys., 10.1143/JJAP.42.L849, 42, 7B, L849-L851, Vol.42, No.7B pp.L849 - L851., 2003.07. |
| 297. | D. Nakagauchi, T. Yoshitake and K. Nagayama, Fabrication of ferromagnetic Fe3Si thin films by pulsed laser deposition using an Fe3Si target, Proceedings of The Seventh International Symposium on Sputtering and Plasma Processes (ISSP2003), 10.1016/j.vacuum.2004.01.065, 74, 3-4, 653-657, pp. 522-525, 2003.06. |
| 298. | T. Yoshitake, M. Yatabe and K. Nagayama, Semiconducting amorphous iron silicide thin films by pulsed laser deposition using a FeSi2 target, Proceedings of The Seventh International Symposium on Sputtering and Plasma Processes (ISSP2003), pp. 530-533., 2003.06. |
| 299. | T. Yoshitake and K. Nagayama, The vane velocity filter for eliminating droplets ejected by pulsed laser deposition, Proceedings of The Seventh International Symposium on Sputtering and Plasma Processes (ISSP2003), pp. 371-374., 2003.06. |
| 300. | Y. Murakami, H. Kido, A. Kenjo, T. Sadoh, T. Yoshitake, M. Miyao, Ion-beam irradiation effect on solid-phase growth of beta-FeSi2, PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, 10.1016/S1386-9477(02)00641-0, 16, 3-4, 505-508, 16 (3-4): 505-508 MAR 2003, 2003.03. |
| 301. | Tsuyoshi Yoshitake, Takeshi Hara, and Kunihito Nagayama, The influence of the repetition rate of laser pulses on the growth of diamond thin films by pulsed laser ablation of graphite, Diamond Rel. Mater., 10.1016/S0925-9635(02)00333-3, 12, 3-7, 306-309, 12, 306-309., 2003.03. |
| 302. | Takeshi Hara, Tsuyoshi Yoshitake, and Kunihito Nagayama, The influence of the repetition rate of laser pulses on the growth of diamond thin films by pulsed laser ablation of graphite, Proceeding of 4th Cross Straits Symposium on Materials, Energy and Environment Sciences, 2002.11. |
| 303. | Tsuyoshi Yoshitake, Gosuke Shiraishi, and Kunihito Nagayama, Elimination of droplets using a vane velocity filter in pulsed laser ablation of FeSi2, Appl. Surf. Sci., 10.1016/S0169-4332(02)00344-6, 197, 379-383, Volumes 197-198, 379-383, 2002.09. |
| 304. | Tsuyoshi Yoshitake, Takashi Nishiyama, Takeshi Hara, and Kunihito Nagayama, Consideration of Growth Process of Diamond Thin Films in Ambient Oxygen by Pulsed Laser Ablation of Graphite, Appl. Surf. Sci., 10.1016/S0169-4332(02)00423-3, 197, 352-356, Volumes 197-198, 352-356, 2002.09. |
| 305. | Hiromitsu Hayashi, Souhachi Iwasa, Nilesh J. Vasa, Tsuyoshi Yoshitake, Kiyotaka Ueda, Shigeru Yokoyama, Sadao Higuchi, Hirohito Takeshita and Michitaka Nakahara, Fabrication of Bi-doped YIG optical thin film for electric current sensor by pulsed laser deposition, Appl. Surf. Sci., 10.1016/S0169-4332(02)00364-1, 197, 463-466, Volumes 197-198 (2002) Pages 463-466, 2002.09. |
| 306. | Tsuyoshi Yoshitake, Takeshi Hara, Takashi Nishiyama, and Kunihito Nagayama, The Roles of ambient oxygen and substrate temperature on growth of diamond thin films by pulsed laser deposition, Int. J. Mod. Phys.B, 10.1142/S0217979202010452, 16, 6-7, 825-829, Vol. 16, Nos. 6 & 7, 825-829., 2002.03. |
| 307. | Hiromitsu Hayashi, Souhachi Iwasa, Nilesh J. Vasa, Tsuyoshi Yoshitake, Kiyotaka Ueda, Shigeru Yokoyama and Sadao Higuchi, Characteristics of Bi:YIG Magneto-Optic Thin Films Fabricated by Pulsed Laser Deposition Method for an Optical Current Transformer, Jpn. J. Appl. Phys., 10.1143/JJAP.41.4101, 41, 1, 410-411, Vol. 41, 410-411, 2002.01. |
| 308. | Tsuyoshi Yoshitake, Takashi Nishiyama and Kunihito Nagayama, "Homo-Growth of Diamond Single Phase Thin Films by Pulsed Laser Ablation of Graphite", Jpn. J. Appl. Phys. Part2, Vol.40, No.6A pp.L573 - L575., 2001.06. |
| 309. | Tsuyoshi Yoshitake, Yusuke Mukae and Kunihito Nagayama, Preparation of calcium silicide thin films on Si(100) and SiO2 substrates by pulsed laser ablation of a Ca2Si alloy target, Trans. Mater. Res. Soci. Jpn, 26, pp. 1207-1210, 2001.04. |
| 310. | Tsuyoshi Yoshitake, Gousuke Shiraishi, and Kunihito Nagayama, "Droplet-free thin films deposited by pulsed laser deposition using a mechanical filter", Jpn. J. Appl. Phys. Part1, Vol. 41, 836-837, 2001.02. |
| 311. | T. Sadoh, Y. Yoshikado, T. Hanada, A. Kenjo, T. Yoshitake, and M. Miyao, Influence of substrate orientation on solid phase regrowth of FeSi2 on Si, Proceeding of Japan-UK Joint Workshop on Kankyo-Semiconductors, pp. 39-41, 2000.12. |
| 312. | Tsuyoshi Yoshitake, Takashi Nishiyama, and Kunihito Nagayama, The Role of Hydrogen and Oxygen Gas in the Growth of Carbon Thin Films by Pulsed Laser Deposition, Diamond Rel. Mater., 10.1016/S0925-9635(99)00240-X, 9, 3-6, 689-692, 9, pp. 689-692, 2000.12. |
| 313. | Tsuyoshi Yoshitake, Takashi Nishiyama and Kunihito Nagayama, Diamond-Like Carbon Thin Films Prepared by Pulsed Laser Ablation of a PMMA and a Polyethylene Targets, Trans. Mater. Res. Soci. Jpn, Volume 25 [1], pp. 321-324,, 2000.12. |
| 314. | Tsuyoshi Yoshitake, Gousuke Shiraishi, and Kunihito Nagayama, Growth of beta-FeSi2 thin films on Si (111) substrates by pulsed laser deposition, Proceeding of Japan-UK Joint Workshop on Kankyo-Semiconductors, pp. 7-9, 2000.10. |
| 315. | Tsuyoshi Yoshitake, Toshifumi Hanada and Kunihito Nagayama, Low Temperature Growth of beta-FeSi2 Films on Si(111) by RF Magnetron Sputtering Using a FeSi2 Alloy Target, J. Mater. Sci. Lett., 10.1023/A:1006722205010, 19, 7, 537-538, 19, pp. 537-538,, 2000.07. |
| 316. | Tsuyoshi Yoshitake, Ion probe measurement of Fe species ejected by KrF laser ablation of Fe in ambient nitrogen gas, J. Mater. Sci, 10.1023/A:1004716526930, 35, 6, 1469-1474, 35 (6), pp. 1469-1474, 2000.06. |
| 317. | Tsuyoshi Yoshitake, Tatsuya Nagamoto and Kunihito Nagayama, Low Temperature Growth of b-FeSi2 Thin Films on Si(100) by Pulsed Laser Deposition, Mater. Sci. Eng. B, 10.1016/S0921-5107(99)00484-5, 72, 2-3, 124-127, Volume 72, Issues 2-3, pp. 124-127,, 2000.03. |
| 318. | Tsuyoshi Yoshitake, Tatsuya Nagamoto and Kunihito Nagayama, Microstructure of beta-FeSi2 Thin Films by Pulsed Laser Deposition, Thin Solid Films, 10.1016/S0040-6090(00)01750-8, 381, 2, 236-243, 381, pp. 236-243, 2000.01. |
| 319. | Toshifumi Hanada, Tsuyoshi Yoshitake, and Kunihito Nagayama, LOW TEMPERATURE GROWTH OF BETA-FESI2 THIN FILMS ON SI (111) BY RF MAGNETRON SPUTTRING USING AN IRON SILICIDE ALLOY TARGET, Proceeding of Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 111-112, 1999.11. |
| 320. | Gousuke Shiraishi, Tsuyoshi Yoshitake, and Kunihito Nagayama, STRUCTURAL CHARACTERIZATION OF BETA-FESI2 THIN FILMS, Proceeding of Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 103-104, 1999.11. |
| 321. | Takashi Nishiyama, Tsuyoshi Yoshitake, and Kunihito Nagayama, GROWTH OF DIAMOND-LIKE CARBON FILMS IN HYDROGEN AND OXYGEN ATMOSPHERE BY PULSED LASER DEPOSITION USING A GRAPHITE TARGET, Proceeding of Cross Straits Symposium on Materials, Energy and Environment Sciences, pp. 101-102, 1999.11. |
| 322. | Tsuyoshi Yoshitake, Tatsuya Nagamoto and Kunihito Nagayama, Low Temperature Synthesis of beta-FeSi2 Thin Films by Pulsed Laser Deposition, J. Mater. Sci. Lett., 10.1023/A:1006671009577, 18, 21, 1755-1756, 18, pp. 1755-1756, 1999.11. |
| 323. | Koji SUIZU, Hajime AOKI, Tsuyoshi YOSHITAKE and Kunihito NAGAYAMA, Emitting Mechanisms of Non-Equilibrium Carbon Particles Emitted by Pulsed Laser Ablation, Proc. 23rd Int. Cong. on High-Speed Photography and Photonics, SPIE, SPIE Vol.3516, Pt.2, pp.379-386, 1999.09. |
| 324. | Tsuyoshi Yoshitake, Takashi Nishiyama, Hajime Aoki, Koji Suizu, Koji Takahashi, and Kunihito Nagayama, Carbon Thin Films Prepared by Pulsed Laser Deposition, Trans. Mater. Res. Soci. Jpn, Vol. 24, No. 4, pp. 599-602, 1999.04. |
| 325. | Tsuyoshi Yoshitake, Tatsuya Nagamoto and Kunihito Nagayama, Fabrication of beta-FeSi2 Thin Films by Pulsed Laser Deposition, Trans. Mater. Res. Soci. Jpn, Vol. 24, No.4, pp. 579-582, 1999.04. |
| 326. | Tsuyoshi Yoshitake, Takashi Nishiyama, Hajime Aoki, Koji Suizu, Koji Takahashi, and Kunihito Nagayama, The Effect of the substrate temperature and the laser wavelength on the formation of carbon thin films by pulsed laser deposition, Diamond. Relat. Mater., 8, pp. 463-467, 1999.03. |
| 327. | Tsuyoshi Yoshitake, Takashi Nishiyama, Hajime Aoki, Koji Suizu, Koji Takahashi, and Kunihito Nagayama, Atomic Force Microscope Study of Carbon Thin Films Prepared by Pulsed Laser Deposition, Appl. Surf. Sci., 10.1016/S0169-4332(98)00601-1, 141, 1-2, 129-137, 141, pp. 129-137, 1999.03. |
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