Electronic structures of silicene/GaS heterosheets

Although Dirac-like electronic properties are predicted for silicene, recent experiments find substrate-induced complex bucklings would destruct such feature [C.-L. Lin et al., Phys. Rev. Lett. 110, 076801 (2013)]. Here, using first-principles calculations, we propose that the recently synthesized gallium sulfide (GaS) nanosheet could be an appropriate substrate for silicene, which can form commensurate Si/GaS heterosheets akin to graphene/BN systems. More importantly, in these heterosheets, the characteristic Dirac-like band feature of linear dispersions is retained, and due to the intrinsic electric field, a sizable band gap is opened at the Dirac point, which could be further tuned by bias voltage or strains. (C) 2013 AIP Publishing LLC.