The linear and nonlinear optical properties of WSxSe2−x (x=0.5, 1.5, and 2.0)

We report calculations of the linear and nonlinear optical properties of WSxSe2−x (x=0.5, 1.5, and 2.0). The anisotropic frequency dependent dielectric function ε(ω) and the second harmonic generation susceptibility χ(−2ω; ω, ω) are evaluated using the full potential-linearized augmented plane wave (FP-LAPW) method. The features in the optical response are explained on the basis of the calculated band structures and density of states. Our calculations show that the new materials WSxSe2−x (x=0.5 and 1.5) possess second harmonic generation (SHG). Also it shows that these materials can be used as nonlinear crystals, which can open new direction to break the inversion symmetry of the transition metal dichalcogenides compounds (TMDCs) in order to find new nonlinear crystals which can be used for different applications.