Abstract
The electronic structure and optical properties of the ternary compound Sn2Sb2S5 have been investigated by using the full potential linear augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). From this study, it is found that the compound Sn2Sb2S5 has direct band gap which is calculated with the GGA and mBJ potentials as 1.22 and 1.51 eV, respectively. Sn2Sb2S5 crystallizes in an orthorhombic structure, with the Pnma space group, the lattice parameters are a = 19.590 angstrom, b = 3.938 angstrom and c = 11.426 angstrom. Optical parameters, such as dielectric constant, refractive index and reflectivity are investigated and analyzed for the first quantitative theoretical prediction of Sn2Sb2S5. The results demonstrated that the compound Sn2Sb2S5 has the potential to be used for photovoltaic and optoelectronic applications.