Electrical and optical behaviors of SiC(GeC)/MoS heterostructures: a first principles study.

Hybrid structures have attracted a great deal of attention because of their excellent properties, which can open up a way we could not foresee in materials science and device physics. Here, we investigate the electrical and optical behaviors of SiC(GeC)/MoS heterostructures, using first principles calculations based on density functional theory. Non-covalent bonding exists between the junctions due to the weak orbital coupling. Both junctions have optically active band gaps, smaller than that of the SiC or GeC and MoS layers, which result in enhanced optical adsorption under visible-light irradiation. A small number of electrons transfer from SiC/GeC to MoS causing its n-doping. Furthermore, the charge density states of the valence band maximum and the conduction band minimum are localized at different sides, and thus the electron-hole pairs are spatially separated. Our results provide a potential scheme for photovoltaic materials.