Image charge effect in layered materials: Implications for the interlayer coupling in MoS2

Abstract

Interlayer coupling often has profound effects on the electronic structure of layered materials. Its strength depends on the ratio between interlayer hopping and band offset. In multilayer materials, the image charge effect causes a layer-dependent variation of the band offset. Here, the authors study the effect of this variation on the interlayer coupling by combining the tight-binding method with an image self-energy. In MoS${}_{2}$, the image charge effect leads to the formation of a surface-layer band gap.