Grain Boundaries in Graphene on SiC(0001虆) Substrate
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- 作者：Yann Tison ; J茅r么me Lagoute ; Vincent Repain ; Cyril Chacon ; Yann Girard ; Fr茅d茅ric Joucken ; Robert Sporken ; Fernando Gargiulo ; Oleg V. Yazyev ; Sylvie Rousset
- 刊名：Nano Letters
- 出版年：2014
- 出版时间：November 12, 2014
- 年：2014
- 卷：14
- 期：11
- 页码：6382-6386
- 全文大小：348K
- ISSN：1530-6992
文摘
Grain boundaries in epitaxial graphene on the SiC(0001虆) substrate are studied using scanning tunneling microscopy and spectroscopy. All investigated small-angle grain boundaries show pronounced out-of-plane buckling induced by the strain fields of constituent dislocations. The ensemble of observations determines the critical misorientation angle of buckling transition 胃c = 19 卤 2掳. Periodic structures are found among the flat large-angle grain boundaries. In particular, the observed 胃 = 33 卤 2掳 highly ordered grain boundary is assigned to the previously proposed lowest formation energy structural motif composed of a continuous chain of edge-sharing alternating pentagons and heptagons. This periodic grain boundary defect is predicted to exhibit strong valley filtering of charge carriers thus promising the practical realization of all-electric valleytronic devices.