Pressure induced effects on the electronic and optical properties of MoS2

Abstract

Using first-principles calculations, including Grimme D2 method for van der Waals interactions, we study the electronic and optical properties of molybdenum disulfide (MoS2) with the application of pressure. The calculated results show the dependences of the electronic and optical properties of the MoS2 on the applied pressure. The effects of van der Waals forces and the Mo–S strong covalent interaction under pressure are different. By contrast, the response of Mo–S covalent bond is more obvious under pressure, which results the CBM cross the Fermi energy firstly, and leads to the metallic state under high pressure. Furthermore, the dielectric function shows that the pressure has the obvious effect on the optical properties. With the incident light perpendicular to the c axis, the dielectric function both real and imaginary part will be shift to red, and the value of peak increases obviously, corresponding to the optical absorption will be enhancement. The conclusions provide a theoretical guidance to improve and optimize the devices performance of MoS2.