Tuning the electronic and optical properties of monolayer MoSe2 by uniaxial tensile strain for optoelectronics

Abstract

Full potential linearized augmented plane wave (FP-LAPW) method is applied to study the electronic and optical properties of MoSe2 monolayer under uniaxial tensile strain. The bandgap of MoSe2 monolayer increases for the application of 1% uniaxial tensile strain and then reduces with increasing the uniaxial tensile strain. The direct bandgap nature of MoSe2 monolayer remain unchanged for 1% and 3% tensile strain. An applied tensile strain of ε=5%, causes a direct to indirect bandgap transition. Analyzing partial density of states (PDOS), the transition of bandgap from direct to indirect is due to the changes of orbital contribution from Mo-dx2-y2 & dz2 to Mo-dz2 states in the conduction band minima (CBM) and Mo-dx2-y2 and Se-pX & pY to Mo-dz2 and Se-pZ states in the valence band maxima (VBM). The enhancement of ε1(ω), ε2(ω) and α(ω) values are observed with uniaxial tensile strain in the visible region. The ε1(0) value increases with increasing tensile strain. The possibility of achieving tunable electronic and optical properties of MoSe2 monolayer with the implementation of uniaxial tensile strain, makes them a potential candidate for optoelectronics.