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arXiv · 1611.08753

Midgap states and band gap modification in defective graphene/h-BN heterostructures

B. Sachs·T. O. Wehling·M. I. Katsnelson·A. I. Lichtenstein
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Abstract

The role of defects in van der Waals heterostructures made of graphene and hexagonal boron nitride (h-BN) is studied by a combination of ab initio and model calculations. Despite the weak van der Waals interaction between layers, defects residing in h-BN, such as carbon impurities and antisite defects, reveal a hybridization with graphene p$_{\rm z}$ states, leading to midgap state formation. The induced midgap states modify the transport properties of graphene and can be reproduced by means of a simple effective tight-binding model. In contrast to carbon defects, it is found that oxygen defects do not strongly hybridize with graphene's low-energy states. Instead, oxygen drastically modifies the band gap of graphene, which emerges in a commensurate stacking on h-BN lattices.

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B. Sachs, T. O. Wehling, M. I. Katsnelson, A. I. Lichtenstein. 2016-11-26. Midgap states and band gap modification in defective graphene/h-BN heterostructures. https://doi.org/10.1103/physrevb.94.224105

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