Experimental Evidence for Epitaxial Silicene on Diboride Thin Films

Abstract

As the Si counterpart of graphene, silicene may be defined as an at least partially $s{p}^2$-hybridized, atom-thick honeycomb layer of Si that possesses $\pi$-electronic bands. Here we show that two-dimensional, epitaxial silicene forms through surface segregation on zirconium diboride thin films grown on Si wafers. A particular buckling of silicene induced by the epitaxial relationship with the diboride surface leads to a direct $\pi$-electronic band gap at the $\Gamma$ point. These results demonstrate that the buckling and thus the electronic properties of silicene are modified by epitaxial strain. DOI: http://dx.doi.org/10.1103/PhysRevLett.108.245501 Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Published by the American Physical Society