Semiconducting Graphene on Silicon from First-Principles Calculations

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• 作者：Xuejie Dang ; Huilong Dong ; Lu Wang ; Yanfei Zhao ; Zhenyu Guo ; Tingjun Hou ; Youyong Li ; Shuit-Tong Lee
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：August 25, 2015
• 年：2015
• 卷：9
• 期：8
• 页码：8562-8568
• 全文大小：508K
• ISSN：1936-086X

文摘

Graphene is a semimetal with zero band gap, which makes it impossible to turn electric conduction off below a certain limit. Transformation of graphene into a semiconductor has attracted wide attention. Owing to compatibility with Si technology, graphene adsorbed on a Si substrate is particularly attractive for future applications. However, to date there is little theoretical work on band gap engineering in graphene and its integration with Si technology. Employing first-principles calculations, we study the electronic properties of monolayer and bilayer graphene adsorbed on clean and hydrogen (H)-passivated Si (111)/Si (100) surfaces. Our calculation shows that the interaction between monolayer graphene and a H-passivated Si surface is weak, with the band gap remaining negligible. For bilayer graphene adsorbed onto a H-passivated Si surface, the band gap opens up to 108 meV owing to asymmetry introduction. In contrast, the interaction between graphene and a clean Si surface is strong, leading to formation of chemical bonds and a large band gap of 272 meV. Our results provide guidance for device designs based on integrating graphene with Si technology.