The Electronic Properties of Single-Layer and Multilayer MoS2 under High Pressure

We analyze the changes in the electronic structures of single-layer and multilayet MoS2 under pressure using first-principles methods including van der Waals interactions. For single-layer MoS2, the bond angle is found to control the electronic structure around the band gap under the pressure. For multilayer and bulk MoS2, the changes in electronic structure under pressure are mainly controlled by the coupling of layers. Under pressure, the band gap of single-layer MoS2 changes from direct to indirect, while multilayer MoS2, becomes a band Metal. Analysis of the real-space distribution of band-decomposed charge density shows that this behavior can be understood in terms of the different Mo d-electron orbitals making up the states near band gap indluding those at-the top of valence band of Gamma and K points and the bottom of conduction band along Lambda and at the K point.