Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Reiji Hattori Last modified date:2023.11.27

Professor / Photonic System Devision / Global Innovation Center / Global Innovation Center


Papers
1. Muhamad Affiq Bin Misran, Rauf Khan, Anubha Bilgaiyan, Reiji Hattori, Photocurrent diffusion of organic photodetector between pixels for fingerprint sensor by using interdigitated electrodes, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.35848/1347-4065/ac89c1, 61, 10, 2022.10, The organic photodetectors (OPDs) with an interdigitated electrodes structure are analyzed to evaluate the optical crosstalk between neighboring pixels for the organic image sensor used in the fingerprint-on-display authentication system. The shorter exciton diffusion length of organic semiconductors in the OPD can promote the high resolution of the organic image sensor for full-display sensing applications. We demonstrated the photocurrent diffusion from the exposed area to the hidden electrodes by changing the distance to predict the minimum pixel pitch for the organic image sensor. Unexpectedly, the photocurrent diffusion was observed, even at 10 mu m length, as more significant than the expected exciton diffusion length..
2. Rauf Khan, Muhamad Affiq Bin Misran, Michitaka Ohtaki, Jun Tae Song, Tatsumi Ishihara, Reiji Hattori, Back-Channel Etched In-Ga-Zn-O Thin-Film Transistor Utilizing Selective Wet-Etching of Copper Source and Drain, PROCESSES, 10.3390/pr9122193, 9, 12, 2021.12, The electrical performance of the back-channel etched Indium-Gallium-Zinc-Oxide (IGZO) thin-film transistors (TFTs) with copper (Cu) source and drain (S/D) which are patterned by a selective etchant was investigated. The Cu S/D were fabricated on a molybdenum (Mo) layer to prevent the Cu diffusion to the active layer (IGZO). We deposited the Cu layer using thermal evaporation and performed the selective wet etching of Cu using a non-acidic special etchant without damaging the IGZO active layer. We fabricated the IGZO TFTs and compared the performance in terms of linear and saturation region mobility, threshold voltage and ON current (I-ON). The IGZO TFTs with Mo/Cu S/D exhibit good electrical properties, as the linear region mobility is 12.3 cm(2)/V-s, saturation region mobility is 11 cm(2)/V-s, threshold voltage is 1.2 V and I-ON is 3.16 x 10(-6) A. We patterned all the layers by a photolithography process. Finally, we introduced a SiO2-ESL layer to protect the device from external influence. The results show that the prevention of Cu and the introduced ESL layer enhances the electrical properties of IGZO TFTs..
3. Suziana Ahmad, Aam Muharam, Reiji Hattori, Anyu Uezu, Tarek M. Mostafa, Shielded Capacitive Power Transfer (S-CPT) without Secondary Side Inductors, ENERGIES, 10.3390/en14154590, 14, 15, 2021.08, In this study, we propose a four-plate structure with two shielding plates to produce shielded capacitive power transfer (S-CPT) at an operating frequency of 6.78 MHz for a 10 W system. By eliminating the inductors at the secondary side to form an asymmetrical topology, an S-CPT system was developed with a class-E power amplifier. Using MATLAB software, analysis was performed to obtain the parameters in the S-CPT system regarding resonance and impedance matching, and the proposed coupler structure was investigated through electric field simulation. The shield plate voltage stability was also investigated by analysing both the simulation and hardware experiment results. A prototype of S-CPT was established to validate the analysis results and to demonstrate the voltage at the shield plate of the proposed coupler structure. The experimental results are in good agreement with the simulation results. The proposed S-CPT exhibits an AC-AC efficiency of 84%, with a 56% voltage ground stability reduction because of implementing a balun..
4. Rauf Khan, Michitaka Ohtaki, Satoshi Hata, Koji Miyazaki, Reiji Hattori, Thermal Conductivity of Nano-Crystallized Indium-Gallium-Zinc Oxide Thin Films Determined by Differential Three-Omega Method., Nanomaterials (Basel, Switzerland), 10.3390/nano11061547, 11, 6, 2021.06, The temperature dependence thermal conductivity of the indium-gallium-zinc oxide (IGZO) thin films was investigated with the differential three-omega method for the clear demonstration of nanocrystallinity. The thin films were deposited on an alumina (α-Al2O3) substrate by direct current (DC) magnetron sputtering at different oxygen partial pressures ([PO2] = 0%, 10%, and 65%). Their thermal conductivities at room temperature were measured to be 1.65, 1.76, and 2.58 Wm-1K-1, respectively. The thermal conductivities decreased with an increase in the ambient measurement temperature. This thermal property is similar to that of crystalline materials. Electron microscopy observations revealed the presence of nanocrystals embedded in the amorphous matrix of the IGZO films. The typical size of the nanocrystals was approximately 2-5 nm with the lattice distance of about 0.24-0.26 nm. These experimental results indicate that the nanocrystalline microstructure controls the heat conduction in the IGZO films..
5. Suziana Ahmad, Reiji Hattori, Aam Muharam, Generalized Circuit Model of Shielded Capacitive Power Transfer, ENERGIES, 10.3390/en14102826, 14, 10, 2021.05, A capacitive power transfer (CPT) system wirelessly transfers energy between coupling plates and performance issues related to CPT systems are resonance conditions, matching impedance, voltage stress, and power loss. A generalized circuit model is proposed for shielded capacitive power transfer (S-CPT) using an algebraic method. The proposed generalized S-CPT model is analyzed based on the symmetric and asymmetric configurations, and the relationship between the parameters of S-CPT is obtained with respect to the resonance condition, matching impedance, voltage stress, and efficiency. The best configuration of a symmetric S-CPT is recommended, and an asymmetric S-CPT is proposed based on the analysis results. Asymmetric-S-CPT hardware was constructed and demonstrated an operating frequency of 13.56 MHz. The hardware experimental result shows the validity and effectiveness of the proposed generalized model for designing S-CPT..
6. Aam Muharam, Suziana Ahmad, Reiji Hattori, Scaling-Factor and Design Guidelines for Shielded-Capacitive Power Transfer, ENERGIES, 10.3390/en13164240, 13, 16, 2020.08, This paper introduces scaling-factor and design guidelines for shielded-capacitive power transfer (shielded-CPT) systems, offering a simplified design process, coupling-structure optimization, and consideration of safety. A novel scaling-factor-analysis method is proposed by determining the configuration of the coupling structure that improves system safety and increases operating efficiency while minimizing the gap between the shield and the coupler plate. The inductor-series resistance is also analyzed to study the loss efficiency in the shielded-CPT system. The relationship among the shield-coupler gap, distance between the couplers, conductive-plate size, and delivered power is examined and presented. The proposed method is validated by implementing the shielded-CPT system with hardware and the result suggests that the proposed method can be used to design shielded-CPT systems with scaling-factor and safety considerations..
7. Anubha Bilgaiyan, Fahed Elsamnah, Hiroshi Ishidai, Chang-Hoon Shim, Muhamad Affiq Bin Misran, Chihaya Adachi, Reiji Hattori, Enhancing Small-Molecule Organic Photodetector Performance for Reflectance-Mode Photoplethysmography Sensor Applications, ACS APPLIED ELECTRONIC MATERIALS, 10.1021/acsaelm.0c00082, 2, 5, 1280-1288, 2020.05, Organic photodetector performance for enhancing the sensing abilities of an organic photoplethysmography sensor was investigated. The optimized organic photodetector with an anode interlayer and a cathode interlayer showed a reverse dark current density of 22 nA cm(-2) at -2 V and an external quantum efficiency of 53.3% at 0 V. This organic photodetector was fabricated monolithically with an organic light-emitting diode on a glass substrate to achieve a reflectance-mode photoplethysmography sensor, demonstrating the impact of organic photodetector device performance on the measured photoplethysmography signal for sensing applications. Furthermore, we estimated the optimal sensor design for circular geometry in terms of device area and distance between the organic light-emitting diode and organic photodetector to maximize the signal-to-noise ratio and lower the power consumption of organic photoplethysmography sensor devices. For the most favorable photoplethysmography sensor design, a signal strength of 130 mV with 600 mu W power consumption was measured..
8. Tarek M. Mostafa, Aam Muharam, Aiguo Patrick Hu, Reiji Hattori, Improved CPT system with less voltage stress and sensitivity using a step-down transformer on receiving side, IET POWER ELECTRONICS, 10.1049/iet-pel.2018.6206, 12, 10, 2634-2641, 2019.08, This paper proposes a capacitive power transfer (CPT) system with a step-down transformer on the secondary side to reduce the circuit quality factor (Q), and thereby reduce the sensitivity to parameters variations, as well as the voltage stress across the coupling interface. The system operating principle is analyzed mathematically, and the focus is given to understand the effect of the leakage inductance (L-lk) of the non-ideal transformer on the system performance. The analytical and simulation results show that at a given constant output power, the voltage across the plates is significantly reduced, and the system becomes less sensitive to the coupling variations by increasing the turns ratio of the step-down transformer. It is found that L-lk can be advantageously utilized as a tuning inductor (L) or part of it. The proposed method is verified by building a prototype CPT system that delivered 25 W at an operation frequency of 1 MHz, and an efficiency of more than 70%. Simultaneously, the voltage stress across the single pair of the coupling plates is reduced from 252 V of a conventional CPT system without a step-down transformer, to 50.4 V using a high-frequency transformer with a turns ratio of 5..
9. Fahed Elsamnah, Anubha Bilgaiyan, Muhamad Affiq, Chang-Hoon Shim, Hiroshi Ishidai, Reiji Hattori, Reflectance-Based Organic Pulse Meter Sensor for Wireless Monitoring of Photoplethysmogram Signal., Biosensors, 10.3390/bios9030087, 9, 3, 2019.07, This paper compares the structural design of two organic biosensors that minimize power consumption in wireless photoplethysmogram (PPG) waveform monitoring. Both devices were fabricated on the same substrate with a red organic light-emitting diode (OLED) and an organic photodiode (OPD). Both were designed with a circular OLED at the center of the device surrounded by OPD. One device had an OLED area of 0.06 cm2, while the other device had half the area. The gap distance between the OLED and OPD was 1.65 mm for the first device and 2 mm for the second. Both devices had an OPD area of 0.16 cm2. We compared the power consumption and signal-to-noise ratio (SNR) of both devices and evaluated the PPG signal, which was successfully collected from a fingertip. The reflectance-based organic pulse meter operated successfully and at a low power consumption of 8 µW at 18 dB SNR. The device sent the PPG waveforms, via Bluetooth low energy (BLE), to a PC host at a maximum rate of 256 kbps data throughput. In the end, the proposed reflectance-based organic pulse meter reduced power consumption and improved long-term PPG wireless monitoring..
10. Fahed Elsamnah, Anubha Bilgaiyan, Muhamad Affiq, Chang-Hoon Shim, Hiroshi Ishidai, Reiji Hattori, Comparative Design Study for Power Reduction in Organic Optoelectronic Pulse Meter Sensor., Biosensors, 10.3390/bios9020048, 9, 2, 2019.03, This paper demonstrated a new design structure for minimizing the power consumption of a pulse meter. Monolithic devices composed of a red (625 nm) organic light-emitting diode (OLED) and an organic photodiode (OPD) were fabricated on the same substrate. Two organic devices were designed differently. One had a circle-shaped OLED in the center of the device and was surrounded by the OPD, while the other had the opposite structure. The external quantum efficiency (EQE) of the OLED and the OPD were 7% and 37%, respectively. We evaluated and compared the signal-to-noise ratio (SNR) of the photoplethysmogram (PPG) signal on different parts of the body and successfully acquired clear PPG signals at those positions, where the best signal was obtained from the fingertip at a SNR of about 62 dB. The proposed organic pulse meter sensor was operated successfully with a power consumption of 0.1 mW. Eventually, the proposed organic biosensor reduced the power consumption and improved the capability of the pulse meter for long-term use..
11. Tarek M. Mostafa, Dai Bui, Aam Muharam, Reiji Hattori, Aiguo Patrick Hu, Capacitive Power Transfer System with Reduced Voltage Stress and Sensitivity, APPLIED SCIENCES-BASEL, 10.3390/app8071131, 8, 7, 2018.07, This paper introduces a DC-DC buck converter on the secondary side of the capacitive power transfer system to reduce the voltage and electric field across the interface, and to reduce the circuit Q, and thus the system sensitivity. The system is mathematically analyzed to study the improvement in sensitivity and voltage stress. The leakage electric field emissions around the plates are investigated by simulation. The analytical and simulation results show that by reducing the duty cycle of the buck converter at a constant output power, the voltage across the plates can be significantly reduced and the circuit becomes less sensitive to the variations in parameters. Experimental results demonstrated that Q and the voltage stress over the capacitive interface are reduced by changing the duty cycle of the buck converter. For delivering 10 W of power, the maximum voltage stress across one pair of the coupling plates is reduced from 211 V in the conventional system without using a DC-DC converter, to 65 V and 44 V at duty cycles of 30% and 20%, respectively. The system achieves an end-to-end power efficiency of 80% at an output power of 10 W and a duty cycle of 30%..
12. Hiroki Hamada, Susumu Horita, Mamoru Furuta, Mutsumi Kimura, Reiji Hattori, Active-Matrix Flatpanel Displays and Devices - TFT Technologies and FPD Materials-, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.7567/JJAP.57.03D001, 57, 3, 2018.03.
13. Reiji Hattori, Special Section Based on Presentations from the 23rd International Display Workshops in conjunction with Asia Display 2016 (IDW/AD '16) Introduction, JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1002/jsid.607, 25, 8, 471-471, 2017.08.
14. C-9-7 Flexible OLED Lighting Panel with Capacitive Coupling Wireless Power Supply.
15. C-9-8 Precise Simulation of Brightness Variation on Whole AMOLED Panel Caused by TFT Characteristics.
16. C-9-7 Precise Simulation of Brightness Variation on Whole AMOLED Panel Caused by Power Line Voltage Drop.
17. Reiji Hattori, Hirotomo Uchiyama, Single Patch Multilayer Aortic Annular Repair for Destructive Infective Endocarditis, JOURNAL OF CARDIAC SURGERY, 10.1111/jocs.12485, 30, 5, 424-426, 2015.05, Active infective endocarditis may progress to annular abscess formation. We describe a patch annuloplasty technique to treat the fragile aortic root tissue in these patients. doi: 10.1111/jocs.12485 (J Card Surg 2015;30:424-426).
18. Susumu Horita, Mamoru Furuta, Reiji Hattori, Mutsumi Kimura, Toshihiko Toyama, Active-Matrix Flatpanel Displays and Devices-TFT Technologies and FPD Materials- FOREWORD, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.7567/JJAP.54.03C001, 54, 3, 2015.03.
19. C-9-10 Skin-Impedance Measurement using the Capacitive Touch Panel.
20. C-9-11 Drive Voltage Optimization and Gray Scale Driving for Electrochromic display.
21. Seung Kyum Kim, Chang-Hoon Shim, Tomohiko Edura, Chihaya Adachi, Reiji Hattori, Improved organic thin-film transistor characteristics using an elevated-electrode structure, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.7567/JJAP.53.111601, 53, 11, 2014.11, We propose a new structure for organic thin-film transistors, denoted as "elevated-electrode structure" in which the source and drain electrodes are formed on the elevated insulation layer. Indeed, the experimental data shows that this new structure has more than twice the drain current and mobility of a conventional bottom-structured TFT, this being found to be directly related to the height of the elevated electrode. Moreover, the reproducibility of this data confirms a greater stability than that of either top-contact or bottom-contact devices. (C) 2014 The Japan Society of Applied Physics.
22. B-21-13 Study of Electrode Shape and Circuit with regards to Capacitive Coupling Wireless Power Transmission.
23. C-9-8 Human-Body-Impedance Measurement using the Capacitive Touch Panel.
24. C-9-9 Projected Capacitive Touch Panel with High Resistive Touch Electrodes for Large Area Touch Screen.
25. C-13-10 Dual-plate OLED Display using low-temperature metal bonding technology.
26. C-9-10 Study of Capacitive Coupling Wireless Power Transmission to Multi-Loads.
27. C-9-4 A Capacitive Sensing Circuit for Distinction of users in the Capacitive Touch Panel.
28. Development of a rectenna for batteryless electronic paper
This paper describes the design of a rectenna for batteryless electronic paper. The rectenna is composed of a one-sided directional flexible antenna and a booster rectifying circuit that is composed of a series resonant circuit and a Cockcroft-walton circuit. The proposed one-sided directional flexible antenna has a bottom floating metal layer that enables one-sided radiation. The booster rectifying circuit has an output of 3.5V DC for an input of 200mV and a 50-ω power source at 920MHz. © 2013 IEEE..
29. Reiji Hattori, Special Section on Electronic Displays FOREWORD, IEICE TRANSACTIONS ON ELECTRONICS, E96C, 11, 1359-1359, 2013.11.
30. Investigation of Capacitive Sensing Circuits for Surface Type Capacitive Touch Panel.
31. Temperature Dependence on Contact Resistances of Organic Thin Film Transistor.
32. Drive Voltage Optimization for Electrochromic Display.
33. C-9-3 Power Consumption Analysis of Electronic Paper.
34. C-9-4 Electric Field Numerical Analysis of Mutual Capacitance Touch Panel.
35. Chang-Hoon Shim, Shuzo Hirata, Juro Oshima, Tomohiko Edura, Reiji Hattori, Chihaya Adachi, Uniform and refreshable liquid electroluminescent device with a back side reservoir, APPLIED PHYSICS LETTERS, 10.1063/1.4749791, 101, 11, 2012.09, We fabricated a refreshable organic light-emitting diode with a liquid emitting layer. This device has a mesh-structured cathode and a liquid reservoir in the back side of the cathode for easy convection of the liquid emitter. The small uniform gap between the electrodes was fabricated by means of micro-electro-mechanical systems (MEMS) processing. Although the device luminance decreased because of decomposition of the liquid emitters under the drive current, the decreased emission was quickly recovered to the initial state by convectional replacement of the decomposed emitters with fresh emitters through the holes of the mesh cathode. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4749791].
36. C-9-1 Circuit design for capacitive coupling wireless power transfer.
37. C-9-2 Study of Capacitive Touch Slider using Transient Electrical Response.
38. CT-1-5 Fundamentals of electronic paper.
39. C-9-1 Transient characteristic measurement for pixel circuit using fine-current measuring system.
40. C-9-2 Electrode Design for electric-field coupling wireless power transfer.
41. Chang-Hoon Shim, Takashi Sekiya, Reiji Hattori, Device Simulation of Ditch and Elevated Electrode Structures in Organic Thin-Film Transistors, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.1143/JJAP.51.024303, 51, 2, 2012.02, A novel organic thin-film transistor structures named the "ditch structure'' or "elevated electrode structure'' is proposed. Device simulations show that the electrical properties of this structure are almost the same as those of a staggered structure (top-contact structure). These results are explained in terms of the electric field concentration at source electrodes with sharp corners and the electric field being vertical to the direction of the gate. The manufacturing process of this structure is as simple as that of a planar structure (bottom-contact structure), and the performance is as high as that of a staggered structure. (C) 2012 The Japan Society of Applied Physics.
42. Design of The Capacitive Sensing Circuit for Development of Single Layered Hybrid Capacitive Touch Panel.
43. Evaluation of power consumption and image quality for fixed-codeword-length coding multi-line addressing organic LED display.
44. Michihiro Asakawa, Sadayuki Kaneko, Reiji Hattori, Shrunk multiline addressing method in a passive-matrix-driven liquid powder display, JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1889/JSID19.10.693, 19, 10, 693-699, 2011.10, A shrunk multiline addressing method (SMLA) in a passive-matrix-driven liquid powder display will be discussed. An algorithm to generate SMLA data that effectively reduces the number of scanning lines has been devised. The update time is reduced by 44.5% on average, and this reduction is maintained despite increased sizes of the images. The SMLA data generated by this algorithm is applied to e-paper panels, thereby confirming the reduction in update time and that the image quality of the panels driven by SMLA is equal to that of conventionally driven ones..
45. Keiichi Betsui, Nobuki Ibaraki, Reiji Hattori, Special Section Based on Presentations from the 17th International Display Workshops (IDW '10) Introduction, JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1889/JSID19.9.575, 19, 9, 575-575, 2011.09.
46. C-9-1 Shrunk Multiline Addressing Driving for Organic Light-Emitting Display and Electronic Paper.
47. Chang-Hoon Shim, Fumito Maruoka, Reiji Hattori, Structural Analysis on Organic Thin-Film Transistor With Device Simulation, IEEE TRANSACTIONS ON ELECTRON DEVICES, 10.1109/TED.2009.2035540, 57, 1, 195-200, 2010.01, A 2-D device simulation for organic thin-film transistors (OTFTs) was carried out to reveal the characteristic difference between staggered and planar structures. Assuming the OTFT with Schottky barrier contact, the staggered-structure TFT has more current flow, bigger field-effect mobility, and lower contact resistance than the planar structure. The simulation results indicate that the source electrode of the staggered structure has better ability to supply the current than that of the planar structure..
48. Chang-Hoon Shim, Reiji Hattori, Fast current programming method for OLEDs using negative capacitor circuit, JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1889/JSID17.7.573, 17, 7, 573-579, 2009.07, To accelerate the settling speed of current programming for AMOLEDs or PMOLEDs, the concept of a "negative capacitor," which consists of a differentiation circuit, an inverting voltage amplifier, and a voltage-to-current converter, was introduced. Circuit simulation showed that this circuit could shorten the settling time to a range of microseconds even for 10 nA of programming current in AMOLEDs. This new driving circuit enabled accurate gray-scale images by using both PWM and PAM methods in PMOLED panels..
49. Reiji Hattori, Chihiro Oishi, Junji Iwasaka, Toshiji Iwasaka, Takayuki Okada, Hiroyuki Johno, Chiharu Enoki, Tomohiko Sumida, Yoshihisa Nakao, Hiroji Imamura, Multiple papillary fibroelastoma with quadricuspid aortic valve, JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY, 10.1016/j.jtcvs.2008.04.015, 137, 5, 1280-1282, 2009.05.
50. C-9-9 Multi-line Addressing.
51. Akihiro Ikeda, Atsushi Sakamoto, Reiji Hattori, Yukinori Kuroki, Electroless Ni-B plating on SiO2 with 3-aminopropyl-triethoxysilane as a barrier layer against Cu diffusion for through-Si via interconnections in a 3-dimensional multi-chip package, THIN SOLID FILMS, 10.1016/j.tsf.2008.09.068, 517, 5, 1740-1745, 2009.01, Electroless Ni-B was plated on SiO2 as a barrier layer against Cu diffusion for through-Si via (TSV) interconnections in a 3-dimensional multi-chip package. The electroless Ni-B was deposited on the entire area of the SiO2 side wall of a deep via with vapor phase pre-deposition of 3-aminopropyl-triethoxysilane on the SiO2. The carrier lifetimes in the Si substrates plated with Ni-B/Cu did not decrease with an increase in annealing temperature up to 400 degrees C. The absence of degradation of carrier lifetimes indicates that Cu atoms did not diffuse into the Si through the Ni-B. The advantages of electroless Ni-B (good conformal deposition and forming an effective diffusion barrier against Cu) make it useful as a barrier layer for TSV interconnections in a 3-dimensional multi-chip package. (C) 2008 Elsevier B.V. All rights reserved..
52. C-9-1 Driving methods of OLED-TV.
53. C-9-2 Acceleration of speed to apply a constant current to OLED.
54. C-9-4 Multi-line Driving of QR-LPD^[○!R] by Non-negative factorization(NMF).
55. Ryo Sakurai, Reiji Hattori, Michihiro Asakawa, Takuro Nakashima, Itsuo Tanuma, Akihiko Yokoo, Norio Nihei, Yoshitomo Masuda, A Flexible electronic-paper display with an ultra-thin and flexible LSI driver using quick-response liquid-powder technology, JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1889/1.2835022, 16, 1, 155-160, 2008.01, A thin and flexible LSI driver with a thickness of less than 35 mu m for a passive-matrix-driven Quick-Response Liquid-Powder Display (QR-LPD (TM)) was successfully mounted onto the flexible printed circuit (FPC) and the back substrates of a flexible QR-LPD (TM). Amounted LSI driver on a plastic substrate shows no significant degradation in the driving performances and maintains physical flexibility without any connection failures. This technology can realize a fully flexible electronic paper in combination with a plastic-substrate QR-LPD (TM) fabricated by a roll-to-roll process..
56. Multi-Line Driving of QR-LPD^【○!R】.
57. Akihiro Ikeda, Tsubasa Saeki, Atsushi Sakamoto, Yosuke Sugimoto, Yasuhiro Kimiya, Yoshiaki Fukunaga, Reiji Hattori, Hisao Kuriyaki, Yukinori Kuroki, Uniformity of an electroless plated Ni on a pad connected to different size pads or a Pn junction for under bump metallurgy in a flip-chip assembly, IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES, 10.1109/TCAPT.2007.901675, 30, 3, 494-499, 2007.09, We investigated electroless Ni uniformity on Al metal pads connected to different size pads or a pn junction for under bump metallurgy in flip-chip assemblies. In an electrically isolated pad, Ni thickness decreased as the pad size decreased. Because of nonlinear diffusion of Ph2+ stabilizer in the plating solution, fewer electrons were supplied to the smaller pad than to the larger pad by an anodic oxidation reaction on the pad surface. In pads smaller than 50 mu m square, the Ni thickness increased when connected to a 100 mu m square pad. This increase might be caused by electrons flowing from the 100 pm square pad to the smaller pad to produce an equipotential for the connected pads. In addition, the Ni thickness was increased by electrical connection to an n-type Si in the presence of fluorescent light illumination for a pn junction area larger than 100 mu m(2). For a pad connected to a p-type Si, however, Ni thickness decreased in comparison to that of an electrically-isolated pad, regardless of the light illumination or pn junction area. The change of Ni height on pads connected to the pn junction is attributable to photoelectrons injected into the n-type Si, or to electron-hole recombination in the p-type Si. These results indicate that the pads should be of the same size within a chip for better Ni uniformity. Moreover, blocking light during Ni electroless; plating can eliminate Ni thickness differences due to an n-type Si connection..
58. The Ubiquitous Society with Electronic Papers - Toward the Electronic Paper Client System.
59. Ryo Sakurai, Shingo Ohno, Shin-ichi Kita, Yoshitomo Masuda, Reiji Hattori, Color displays and flexible displays using quick-response liquid-powder technology for electronic paper, JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1889/1.2709732, 15, 2, 127-131, 2007.02, Color displays and flexible displays that use electronic liquid powder have been developed. Novel types of color displays using either a colored powder or a color filter are discussed. We have also developed a flexible display with low-cost substrate films with a high-throughput roll-to-roll manufacturing method. These technologies enable a QR-LPD to be widely used as an electronic-paper display..
60. Estimation of Contrast Ratio in QR-LPD^【○!R】 by Four-Voltage Level Driving.
61. Yoshitomo Masuda, Norio Nihei, Ryo Sakurai, Reiji Hattori, A reflective-display QR-LPD (R), JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 10.1889/1.2206107, 14, 5, 443-448, 2006.05, A novel reflective display [Quick-Response Liquid Powder Display (QR-LPD(R))], has been developed. This paper-like display has the advantages of outstanding image stability, easy viewing, low-power consumption, and a high-response time. QR-LPD(T) will be promoted, initially, for use as electronic price-tag displays for merchandise. In addition, QR-LPD(R) is suitable for flexible display applications because it does not require TFT arrays or a high-temperature process while maintaining an excellent paper-like image as well as glass-type display compatibility..
62. スギモト シンタロウ, ハットリ レイジ, Analysis of Optimum Current Memory Circuit in Single DAC Current Delivery System for AM-OLED Panel: 単一DAC電流配分法AM-OLEDパネル内電流メモリー回路の解析: 発光型/非発光型ディスプレイ合同研究会, 104, 620, 53-56, 2005.01.
63. スギモト シンタロウ, ハットリ レイジ, Analysis of Optimum Current Memory Circuit in Single DAC Current Delivery System for AM-OLED Panel: 単一DAC電流分配法AM-OLEDパネル内電流メモリー回路の解析: 発光型/非発光型ディスプレイ合同研究会, 29, 3, 53-56, 2005.01.
64. YIP Gordon, SUGIMOTO Shintarou, HATTORI Reiji, 単一DAC電流分配法AM-OLEDパネル内電流メモリー回路の解析, 2005, 1, 53-56, 2005.01.
65. Gray Scale for QR-LPD^【○!R】.
66. Fujimura Tsuyoshi, Ikeda Akihiro, Etoh Shin-ichi, Hattori Reiji, Kuroki Yukinori, Chang Suk Sang, Fabrication of Open-Top Microchannel Plate Using Deep X-Ray Exposure Mask Made with Silicon On Insulator Substrate, Japanese journal of applied physics. Pt. 1, Regular papers & short notes, 10.1143/JJAP.42.4102, 42, 6, 4102-4106, 2003.06, We propose a high-aspect-ratio open-top microchannel plate structure. This type of microchannel plate has many advantages in electrophoresis. The plate was fabricated by deep X-ray lithography using synchrotron radiation (SR) light and the chemical wet etching process. A deep X-ray exposure mask was fabricated with a silicon on insulator (SOI) substrate. The patterned Si microstructure was micromachined into a thin Si membrane and a thick Au X-ray absorber was embedded in it by electroplating. A plastic material, polymethylmethacrylate (PMMA) was used for the plate substrate. For reduction of the exposure time and high-aspect-ratio fast wet development, the fabrication condition was optimized with respect to not the exposure dose but to the PMMA mean molecular weight (M.W.) changing after deep X-ray exposure as measured by gel permeation chromatography (GPC). Decrement of the PMMA M.W. and increment of the wet developer temperature accelerated the etching rate. Under optimized fabrication conditions, a microchannel with 50 μm width through 1000 μm PMMA plate, with a high aspect ratio over 20, was fabricated. By using a high-aspect-ratio open-top microchannel plate, high fluorescent electrophoresis was performed..
67. Current-Writing Active-Matrix Driving Circuit for Organic Light Emitting Diode Display.
68. Current-setting-type active-matrix driving circuit for Organic LED.
69. Yi He, Reiji Hattori, Jerzy Kanicki, Electrical Reliability of Two- and Four- a-Si:H TFT Pixel Electrode Circuits for Active-Matrix OLEDs, Proceeding of Society for Information Display, 2000 International Symposium, pp.354-357, 2000.01.
70. Application of a polysilane EL device to display
We have fabricated electroluminescent devices using Poly (dimethylsilane) (PDMS) deposited film as an active layer, and discussed an application to display as a ultraviolet-excitation source. We can demonstrated the red (R), green (G) and blue (B) light emission devices by combining with RGB phosphors. The luminance of the green-light emitting device is 0.2 cd/m^2 and the half-value lifetime is about 5 hours at 250K. These results show a possibility of application to a full-color flat panel display using a PDMS-EL device..
71. Properties and Applications of Films Prepared by Evaporation of Organopolysilane
This paper describes the physical properties and the applications of the films prepared by the evaporation of poly(di-methyl silane). The orientation of the films can be controlled by changing the growth rate of the film. The electric conductivity along the main chain is larger than that perpendicular to the chain. These films are expected to be used as electron beam resist as well as optical device material. The electro-luminescence device fabricated has a thin film whose thickness is less than 0.1 μm, and shows a broad spectrum from 350 to 650 nm..
72. Orientation Control and Photoemission Properties of Poly(dimethylsilane)
We have prepared epitaxially grown poly(dimethylsilane) (PDMS) films the silicon chains of which were pallarel to and perpendicular to the substrate by evaporating PDMS powder source, and observed the photoe-mission properties of these films. These configrations were observed by x-ray diffraction and atomic force microscopy (AFM). From the photoluminescence(PL), exitation and absorption spectroscopies, we found that the photoemission takes place from the longest delocalized region in silicon backbone and the region is widened by the orientaion or crystallization. Disorderness of the films were observed to be reduced by the epitaxial growth, which makes the stoks sift little and PL intensity strong..
73. Preparation and Estimation of poly-Si TFT Empoying Schottky Barrier Contacts at Source and Drain
Poly-Si TFT with Schottky Barrier Contacts composed of Yttrium silicide/poly-silicon at Source and Drain has been prepared. The structure of this TFT has no n+ region and the source and drain electrodes can be fabricated by a self-align process. This results in drastic reduction of the fabrication process of TFT gate-array and the large cost down. We also estimated the optimum annulling temperature from the current-voltage characteristics of Yttrium silicide/poly-silicon contacts formed on (111) surface of p-type crystalline silicon. The fabricated poly-Si TFT shows the n-channel transistor action and the probability of application to the TFT plat panel display..
74. Fabrication and Electrical Properties of Yttrium Silicide/Silicon
Yttrium silicides have been fabricated both on Si(111)and on a- Si by the vacuum annealing.The relation of the annealing temperature with the silicide structure and with the electrical property is investigated.On Si(111),above the annealing temperature of 300℃,Yttrium disilicide(YSi_2-x>)grows and shows t he low Schottky barrier height with n-type silicon.However,above 400℃,the oxidization of silicide progresses and courses the increa se of barrier height and the reduction of the on-current.In the case of a-Si,the silicide grows above the 300℃,the junction anneal ed at 400℃ shows the best ohmic propertiy..
75. Numerical anarysis of Schottky barrier tunnel transistor(SBTT)
Schottky barrier tunnel transistor(SBTT)is one of the tunnel transistor.with a new operating principle which employs the tunneling current trough the Schottky barrier,and is expected to be a promising element device for high-density integrated circuits and for low-cost fabricating processes.In this paper we firstly show the physical model for numerical analysis of reverse tunneling current through the Schottky junction which are significant for SBTT device simulation,and the numerical procedure for device simulator with the finite difference method.Secondly,we carry out 2-D device simulation on the simplified structure,and show the limit and the optimized value for impurity density, channel thickness,channel length and barrier height..