First-principles study of electronic and optical properties of antimony sulphide thin film

Abstract

First-principles quantum mechanical computational methods are significant tools to understand the details of crystal structures which might be difficult through experimentation. In this paper, we have presented the electronic and optical properties of the thin film structure of Sb2S3 in (001) orientation. Density functional theory based approaches are employed to determine the band structure, density of states (DOS), dielectric function and other optical parameters. Here, the investigations have been performed by full-potential linearized augmented plane-wave method (FP-LAPW) within the WIEN2k computational code. The band structure computations are done at the level of LDA-PW, PBE-GGA, PBE-GGA with SOC and PBE-GGA with mBJ potential, whereas for optical properties only PBE-GGA with mBJ potential was applied. Our calculations revealed that similar to optical properties, Sb2S3 (001) oriented thin film had shown a reduction in the band gap energy than its counterpart bulk structure. This reduction, in the electronic and optical parameters, might be better understood in the course of quantum confinement effect for improving its performance for optoelectronics applications.