Indium dopant-induced morphological and optical properties of tin-antimony sulfide thin films synthesized by the spin coating method compared with ab initio calculation

Abstract

In3+-doped tin antimony sulfide (TAS) thin films were synthesized by a spin coating method, and their optical properties compared to ab initio investigation. Various In3+ doping concentrations significantly affected the morphological changes of TAS thin films. XRD patterns indicated the characteristics of monoclinic Sn6Sb10S21 and orthorhombic Sn5Sb2S9 structures. Band gaps were calculated from Tauc plots and varied with In concentration from 1.59 to 1.98 eV. The calculated results confirmed the indium dopant acting as an impurity state, which is a key factor for improving photo-absorption. This report indicates the promising performance of the optimum indium doping in the TAS film for high-potential optoelectronic devices.