Wide Band Gap Semiconductor from a Hidden 2D Incommensurate Graphene Phase
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- 作者：Matthew ConradFeng Wang ; Meredith Nevius ; Katherine Jinkins ; Arlensiú Celis ; Maya Narayanan Nair ; Amina Taleb-Ibrahimi ; Antonio Tejeda ; Yves Garreau ; Alina Vlad ; Alessandro Coati ; Paul F. Miceli ; Edward H. Conrad
- 刊名：Nano Letters
- 出版年：2017
- 出版时间：January 11, 2017
- 年：2017
- 卷：17
- 期：1
- 页码：341-347
- 全文大小：482K
- ISSN：1530-6992
文摘
Producing a usable semiconducting form of graphene has plagued the development of graphene electronics for nearly two decades. Now that new preparation methods have become available, graphene’s intrinsic properties can be measured and the search for semiconducting graphene has begun to produce results. This is the case of the first graphene “buffer” layer grown on SiC(0001) presented in this work. We show, contrary to assumptions of the last 40 years, that the buffer graphene layer is not commensurate with SiC. The new modulated structure we’ve found resolves a long-standing contradiction where ab initio calculations expect a metallic buffer, while experimentally it is found to be a semiconductor. Model calculations using the new incommensurate structure show that the semiconducting π-band character of the buffer comes from partially hybridized graphene incommensurate boundaries surrounding unperturbed graphene islands.