First principles prediction of the elastic, electronic, and optical properties of Sb_2S_3 and Sb_2Se_3 compounds

摘要

We have performed a first principles study of structural, mechanical, electronic, and optical properties of orthorhombic Sb_2S_3 and Sb_2Se_3 compounds using the density functional theory within the local density approximation. The lattice parameters, bulk modulus, and its pressure derivatives of these compounds have been obtained. The second-order elastic constants have been calculated, and the other related quantities such as the Young's modulus, shear modulus, Poisson's ratio, anisotropy factor, sound velocities, Debye temperature, and hardness have also been estimated in the present work. The linear photon-energy dependent dielectric functions and some optical properties such as the energy-loss function, the effective number of valence electrons and the effective optical dielectric constant are calculated. Our structural estimation and some other results are in agreement with the available experimental and theoretical data.