Contracted interlayer distance in graphene/sapphire heterostructure

作     者：Shiro Entani Liubov Yu. Antipina Pavel V. Avramov Manabu Ohtomo Yoshihiro Matsumoto Norie Hirao Iwao Shimoyama Hiroshi Naramoto Yuji Baba Pavel B. Sorokin Seiji Sakai 

作者机构：Advanced Science Research Center Japan Atomic Energy Agency Tokai Ibaraki 319-1195 Japan Technological Institute for Superhard and Novel Carbon Materials Troitsk Moscow 142190 Russia Moscow Institute of Physics and Technology Dolgoprudny Moscow 141700 Russia Siberian Federal University 79 Svobodniy pr. Krasnoyarsk 660041 Russia Ouantum Beam Science Directorate Japan Atomic Energy Agency Tokai Ibaraki 319-1195 Japan National University of Science and Technology MISiS Moscow 119049 Russia 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2015年第8卷第5期

页      面：1535-1545页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 081702[工学-化学工艺] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0817[工学-化学工程与技术] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：We are grateful to the 'Chebishev' and 'Lomonosov' supercomputers of Moscow State University for providing the chance of using a cluster computer for quantum-chemical calculations. S.E. thanks Prof. H. Kondo (Keio University) and Prof. T. Shimada (Hirosaki University) for NIXSW measurements. This work was partly supported by Grants-in-Aid for Young Scientists B (Grant No. 22760033) from the Japan Society for the Promotion of Science. The present work has been performed under the approval of the Photon Factory Program Advisory Committee (PF PAC Nos. 2010G660 and 2012G741). P.V.A.  P.B.S. and L.Y.A. acknowledge the support from the Russian Science Foundation (project No. 14-13-00139) 

主　　题：graphene sapphire chemical vapor deposition graphene/insulator interface 

摘      要：Direct growth of graphene on insulators is expected to yield significant improvements in performance of graphene-based electronic and spintronic devices. In this study, we successfully reveal the atomic arrangement and electronic properties of a coherent heterostructure of single-layer graphene and α-Al2O3（0001）. The analysis of the atomic arrangement of single-layer graphene on α-Al2O3（0001） revealed an apparentcontradiction. The in-plane analysis shows that single-layer graphene grows not in a single-crystalline epitaxial manner, but rather in polycrystalline form, with two strongly pronounced preferred orientations. This suggests relatively weak interfacial interactions are operative. However, we demonstrate that unusually strong physical interactions between graphene and α-Al2O3（0001） exist, as evidenced by the small separation between the graphene and the α-Al2O3（0001） surface. The interfacial interaction is shown to be dominated by the electrostatic forces involved in the graphene n-system and the unsaturated electrons of the topmost O layer of α-Al2O3（0001）, rather than the van der Waals interactions. Such features causes graphene hole doping and enable the graphene to slide on the α-Al2O3（0001） surface with only a small energy barrier despite the strong interfacial interactions.