Bandgap engineering and tuning of optoelectronic properties of 2D NbSe2/MoS2 heterostructure using first principle computations

Abstract

This study performed first-principles calculations based on density functional theory to study the interlayer electronic and optical properties of NbSe2/MoS2 heterostructures. Bandgap in 2H-MoS2 is often quite large typically around 1.8 eV, showing slow response time and low photoresponsivity (R); however, a slight bandgap variation can improve the properties of semiconducting and conducting heterostructures. Different stacking configurations of the interlayer van der Waals interaction were precisely investigated. Due to their unique properties, atomically thin NbSe2/MoS2 based heterostructures hold great potential for future electronic and optoelectronic devices. LDA, GGA, GGA with SOC, and HSE06 are used to study the monolayers of MoS2, NbSe2, and their T and H stacking structures. Our results demonstrate that the metallic NbSe2 effect on the semi-metallic MoS2 reduces the band gap of MoS2 up to 140 meV. Moreover, these heterostructures exhibit outstanding absorption properties from visible to ultraviolet regions, which makes them ideal candidates for optoelectronic applications, particularly in photodetectors.