SiC衬底上石墨烯的性质、改性及应用研究

doi:10.6023/A12070398

摘要/Abstract

大面积高质量石墨烯的制备及其改性对于纳电子器件相关研究有重要意义. 本文综述了近年来SiC衬底上石墨烯的相关研究, 包括外延法制备石墨烯、石墨烯与SiC衬底的作用机理、SiC衬底上石墨烯的改性方法以及外延石墨烯在器件等方面应用的重要进展. 目前, 外延法的工艺较为成熟且制备的较大面积石墨烯品质较好. SiC衬底和石墨烯之间的相互作用与衬底的表面原子种类、表面态、原子成键、钝化程度、电荷转移等密切相关, 其对石墨烯的电子能带、载流子种类产生明显影响. 实验与理论计算的结合可望加深对SiC衬底与石墨烯作用机理的理解, 并指导外延石墨烯改性及其在器件应用方面的进一步研究.

关键词: 石墨烯, 衬底, SiC, 改性, 外延法

It is significant to prepare large-scale and high-quality graphene on SiC substrate for the research of the device in nanoelectronics. This review presents a brief overview on the progress in the growth mechanism for epitaxial graphene on SiC substrate surface, the methods of modification and the research of graphene-based devices. Graphene has attracted the interest of the scientists due to its exceptional electronic properties, which make it a promising material for nanoelectronics. Nowadays, the high-quality epitaxial graphene can be obtained with the smooth morphology, few defects, large size by controling the environment, annealing temperature and vapor pressure. The special structure that the first carbon layer grown above the Si-terminated SiC substrate form strong covalent bonds with substrate, results in some unusual properties such as opening a band gap in the graphene bilayer and a n-type doping of the graphene layers. The rotated fault, which is owed to decoupling effect, has been observed in C-terminated multilayer graphene. And such intrinsic properties of graphene depend on the atom type of SiC surface, surface state, weakness of bonds and the transformation of the electrons between the few- layer graphene and SiC substrate. Some limitations (such as little band gap, intrinsic n-type character, etc.) resulted from the properties of epitaxial graphene must be overcome for the device application. Thus tremendous effort has been devoted to achieve the deliberate control of the band gap, the density and character of its charge carriers. Having a deep understanding of the unique properties for epitaxial graphene, this article then selectively reviews modification methods by considing the type of atoms, size of atoms, work function and electron affinity. In order to manufacture well-behaved devices, many of the fundamental problems of graphene-based eletronics, including methods to make metal contacts, nanoscale patterning and other technical details should be addressed perfectly. It is also important to control the material of gate, modulate the face of substrate, the width of channel in order to improve the performance of the graphene-based devices such as carrier mobility and I_on/I_off ratios. The combination between the experiment and calculation (such as Monte Carlo simulation, density functional theory, molecular dynamics simulation etc.) can make a deeper understanding of the effects of SiC substrate and the methods of modification, which can be served as a guide for further research.

Key words: graphene, substract, SiC, modification, epitaxy

引用此文

方楠, 刘风, 刘小瑞, 廖瑞娴, 缪灵, 江建军. SiC衬底上石墨烯的性质、改性及应用研究[J]. 化学学报, 2012, 70(21): 2197-2207.

Fang Nan, Liu Feng, Liu Xiaorui, Liao Ruixian, Miao Ling, Jiang Jianjun. Progress of Properties, Modification and Applications of Graphene on SiC Substrate[J]. Acta Chimica Sinica, 2012, 70(21): 2197-2207.

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