Synchrotron X-ray standing wave Characterization of atomic arrangement at interface between transferred graphene and α-Al2O3 (0001)
Synchrotron X-ray standing wave Characterization of atomic arrangement at interface between transferred graphene and α-Al2O3 (0001)
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DOI：
10.1016/j.susc.2020.121749
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发表时间：
2021-02-01
期刊：
影响因子：
1.9
通讯作者：
Sakai, Seiji
中科院分区：
文献类型：
--
作者：
Entani, Shiro;Honda, Mitsunori;Sakai, Seiji
石墨烯有望成为纳米电子学和自旋电子学最有前途的材料之一。在大多数基于石墨烯的器件中，石墨烯通道放置在绝缘基板上。因此，研究石墨烯与绝缘子表面的界面相互作用具有重要意义。用正入射X射线驻波(NIXSW)技术研究了石墨烯在α-Al_2O_3(0001)上的垂直排列。NiXSw剖面分析表明，石墨烯位于α-Al_2O_3(0001)表面上方3.57埃，大于石墨层间距离(3.356埃)。显微拉曼光谱表明，所转移的石墨烯具有有限的空穴浓度空间分布。研究表明，蓝宝石衬底上转移的石墨烯经过真空退火后，表面原子平整，没有有机化合物等残留污染物，石墨烯中存在空穴掺杂。
Graphene is expected to be one of the most promising materials for nanoelectronics and spintronics. In most graphene-based devices, the graphene channel is placed on insulating substrates. Therefore, the study of interfacial interactions between graphene and the insulator surface is of critical importance. In this study, the vertical arrangement of graphene which is transferred on alpha-Al2O3(0001) has been studied by normal incidence X-ray standing wave (NIXSW) technique. The analysis of the NIXSW profile reveals that the graphene layer is located at 3.57 angstrom above the alpha-Al2O3(0001) surface, which is larger than the interlayer distance of graphite (3.356 angstrom). Micro Raman spectroscopy shows that the transferred graphene has a limited spatial distribution of hole concentration. The present study shows that transferred graphene on the sapphire substrate followed by vacuum-annealing has an atomically flat surface free from residual contaminations such as organic compounds and there occurs the hole-doping in graphene.