Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Tanaka Satoru Last modified date:2019.06.21

Professor / Applied Physics / Department of Applied Quantum Physics and Nuclear Engineering / Faculty of Engineering

1. Takashi Kajiwara, Anton Visikovskiy,Takushi Iimori,Toshio Miyamachi,Fumio Komori,Satoru Tanaka, Graphene transfer on periodic SiC nanosurfaces, International Symposium on Epitaxial Graphene 2017 (ISEG2017), 2017.11, Graphene growth by thermal decomposition of SiC(0001) surface is more advantageous than other methods because of epitaxial nature on wafer scale. However, the electrical properties are somehow limited by the presence of surface steps and excess bilayer, which causes the carrier scattering and thus degrade the mobility. To solve the problems exfoliation and transferring of epitaxial graphene grown SiC has recently been paid attention. However, the transfer of monolayer graphene directly from a SiC surface is difficult because its relatively strong interaction with a buffer layer ((6√3 ́6√3)R30° structure (6R3)). J. Kim et al. reported a layer resolved graphene transfer technique from SiC surface using Ni stressor layer1. They demonstrated that the electronic properties of graphene are remarkably improved by deleting the bilayer region and transferring it to a flat surface2. In addition, transferring monolayer graphene with defined crystal orientation to various substrates enables to realize controllable moiré superstructures, which shows fractal quantum Hall effects3..
2. Shingo Hayashi, Takashi Kajiwara, Anton Visikovskiy, Takushi Iimori, Tetsuro Shirasawa, Kan Nakastuji, Toshio Miyamachi, Syuhei Nakashima, Kazuhiko Mase, Fumio Komori, Satoru Tanaka, Sn atomic layer by intercalation at graphene / SiC interface, International Symposium on Epitaxial Graphene 2017 (ISEG2017), 2017.11, Researches on atomic layer materials of group IV elements attracts great attention. Among them,
stanene, an atomic layer of Sn, is expected to exhibit such unique characteristics as a two dimensional topological insulator [1] and quantum anomalous Hall effect [2]. The growth of stanene on Bi2Te3 has been achieved [3] but no experimental evidence on such characteristics is yet reported. On the other hand, since Sn shows a large spin orbit coupling (SOC), the spin and electronic states in terms of Rashba splitting, antiferromagnetic order and Mott insulator transition etc. are investigated. Adatom Sn (√3×√3) R30° (R3) structure on semiconductor substrates (Ge, SiC) has been reported [4, 5]. Thus, we have been aiming at forming stanene on SiC(0001) surfaces. Here, we tried Sn intercalation at graphene/SiC interfaces, which are advantageous to any ex-situ measurements of a Sn interlayer..
3. Anton Visikovskiy,Shingo Hayashi,Fumio Komori, Satoru Tanaka, Sn and Pb triangular lattice atomic layers on SiC(0001) and at graphene/SiC(0001) interface
, International Symposium on Epitaxial Graphene 2017 (ISEG2017), 2017.11, The research of 2D Dirac materials has been one of the main topics in recent material science, because of wide possible device application and fascinating physics. Most studies, however, are concentrated on graphene-like honeycomb lattice materials (graphene, silicene, germanene, stanene, etc.)1,2, though other lattice types may possess similar electronic structure features. Dense triangular lattice atomic layers (TLAL) of heavy group IV elements (Sn, Pb) on SiC(0001) surface and at graphene/SiC(0001) interface could be such materials (Fig. 1a,b). Additionally, heavy group IV elements exhibit strong spin-orbit coupling (SOC) which may significantly contribute to electronic structure of 2D layers and result in spin-polarized states. Previous studies did consider sparse triangular systems of group IV adatoms on SiC surface in terms of frustrating magnetic order, spin liquids, and Mott-type insulator state3. However, dense atomic layers where Sn (or Pb) atoms directly interconnected by in-plane bonds are unexplored..
4. Kohei Fukuma, Anton Visikovskiy, Shingo Hayashi, Takashi Kajiwara,Takushi Iimori,Fumio Komori, Satoru Tanaka, Graphene nanoribbons grown on facets resulted from macro-step bunching on vicinal SiC surfaces, International Symposium on Epitaxial Graphene 2017 (ISEG2017), 2017.11, Graphene is expected to be used for the next generation ultra-fast switching devices. For this purpose the bandgap opening is the central issue and thus graphene nanoribbons1 (GNRs) have been investigated by many researchers. We reported GNR growth on periodic nanofacet SiC surfaces by molecular beam epitaxy (MBE) and showed the bandgap opening at K-point by angle-resolved photoemission spectroscopy (ARPES)2. We also found the periodically rippled graphene on the facets on vicinal SiC substrates via surface decomposition. As is illustrated in Fig. 1 GNR-like layer is possibly present at the interface3. To investigate the “real” feature of the interface layer by STM/STS, Raman spectroscopy, and LEED we tried to remove the top rippled graphene..
5. A. Visikovskiy, S.-I. Kimoto, T. Kajiwara, M. Yoshimura, F. Komori, S. Tanaka, Graphene/SiC(0001) interface variety induced by Si intercalation, 18th International Conference of Crystal Growth and Epitaxy (ICCGE18), 2016.08, Graphene is an important 2D material with extremely useful properties for device applications. Growth of graphene on substrates faces the problem of interface influence on graphene's properties. In particular, graphene forms buffer layer when growing on SiC(0001) which does not possess characteristic graphene band dispersion and affect, often negatively, subsequent graphene layers. The interface between graphene and SiC can be modified by different atoms intercalation. In the present work, we consider one of the simplest case of Si intercalation. Various amounts of Si atoms were intercalated into graphene/SiC(0001) interface and studied by means of electron diffraction (LEED, RHEED), scanning tunneling microscopy (STM), angle-resolved photoemission (ARPES) and computational methods. We have shown that interface structures are similar to those formed by Si adsorption on clean SiC(0001) surface. The formation of these interface structures decouples graphene layer from substrate and restore it's linear electronic band dispersion..
6. T. Takasaki, J. Shioji, T. Kajiwara, A. Visikovskiy, S. Tanaka, Anisotropic growth of graphene on cleaved SiC(1-100) surfaces, 18th International Conference of Crystal Growth and Epitaxy (ICCGE18), 2016.08, Graphene nanoribbons (GNRs) are of importance for switching device applications because of possible bandgap opening at K-points. Many approaches have been proposed to tailor narrow ribbons, however, so far no effective or practical method is achieved.
SiC is known to be a good template for graphene epitaxial growth via surface decomposition. There have been many researches on polar SiC(0001) surfaces, on which an uniform thick graphene layer is grown. This structure is beneficial to investigate Dirac physics in terms of crystal quality. In order to modify electronic structure at K-points of graphene on such SiC substrates, e.g. bandgap creation, it is necessary to consider alternating growth ideas. We here demonstrate graphene growth on nonpolar SiC(1-100) surfaces [1, 2] showing lower crystal symmetry, that may induce anisotropic graphene growth, and thus GNR formation..
7. Tanaka Satoru, Takashi Kajiwara, ANTON VISIKOVSKIY, Graphene lateral superlattices formed on SiC facets - semiconducting and ballistic transport -
, 2015 MRS Fall Meeting , 2015.11.
8. Tanaka Satoru, Takashi Kajiwara, ANTON VISIKOVSKIY, Sub 2‐dimensional graphene nanostructures formed on SiC(1‐108) facets ‐ semiconducting and ballistic transport, 16th International Conference on Silicon Carbide and Related Materials(ICSCRM2015), 2015.10.
9. Tanaka Satoru, Quasi-one-dimensional graphene nanostructure on corrugated SiC surfaces, 21st International Conference on Electronic Properties of Two-Dimensional Systems 17th International Conference on Modulated Semiconductor Structures, 2015.07.
10. Tanaka Satoru, Semiconducting characteristics in self-ordered quasi-one dimensional graphene lateral superlattice, NT-15, 2015.06.
11. Tanaka Satoru, One-dimensional Si adatom induced nanoribbon formation on SiC surface during molecular beam epitaxy, IUMRS-IECM 2012, 2014.08.
12. Shingo Hayashi, Takashi Kajiwara, ANTON VISIKOVSKIY, Tanaka Satoru, Intermediate C-Rich (Sqrt [3] x Sqrt [3]) R30 Structure Preceding Graphene Buffer Layer Formation on SiC (0001), ICSCRM2013, 2013.10.
13. Shin-ichi Kimoto, Takashi Kajiwara, ANTON VISIKOVSKIY, Tanaka Satoru, Silicon Intercalation at the SiC-Graphene Interface, ICSCRM2013, 2013.09.
14. Tanaka Satoru, Takashi Kajiwara, ANTON VISIKOVSKIY, Bandgap Opening on Graphene Nanoribbons Grown on Vicinal 6H- and 4H-SiC Surfaces by Molecular Beam Epitaxy, ICSCRM2013, 2013.09.
15. Tanaka Satoru, Growth of graphene nanoribbon arrays on vicinal SiC surfaces by molecular beam epitaxy, Physical Sciences Symposia-2013, 2013.09.
16. Tanaka Satoru, Graphene nanoribbons grown by molecular beam epitaxy, IUMRS-IECM 2012, 2012.09.
17. Takashi Kajiwara, Tanaka Satoru, Epitaxial Graphene Nanoribbons Grown by Molecular Beam Epitaxy, 2012 MRS Fall Meeting, 2012.11.
18. Yoshihito Hagihara, Tanaka Satoru, Graphene Growth on SiC Nanofacet Surfaces by Chemical Vapor Deposition, 2012 MRS Fall Meeting, 2012.11.
19. 中森 弓弦, Tanaka Satoru, Raman Spectroscopy of Epitaxial Graphene Nanoribbons, 2012 MRS Fall Meeting, 2012.11.
20. Epitaxial SiO/SiN superstructures on SiC surfaces.