First Principle Study for Optical Properties of TMDCs/Graphene Heterostructures

Abstract

The transition-metal dichalcogenide (TMDC) in the family of MX2 (M = Mo, W; X = S, Se) and the graphene monolayer are atomically thin semiconductors and semimetal, respectively. The monolayer MX2 have been discovered as a new class of semiconductors for electronics and optoelectronics applications. Because of the hexagonal lattice structure of both the materials, MX2 and graphene are often combined with each other to make van der Waals heterostructures. Here, the MX2/graphene heterostructures are investigated theoretically based on the Density Functional Theory (DFT). The electronic structure and the optical properties of four different MX2/graphene heterostructures are computed. We systematically compare these MX2/Gr heterostructures for their complex permittivity, absorption coefficient, reflectivity and refractive index.