Structural and electronic properties of β-In2X3 (X = O, S, Se, Te) using ab initio calculations

Several III-VI body-centered tetragonal layered compounds belonging to space group I41/amd have been a subject of interest recently because of their potential applications in high efficiency and environmentally friendly copper-indium-gallium-selenide solar cells and molecules. Here we have studied the structural, energetic, and electronic properties of four compounds β-In2X3 (X = O, S, Se, Te), in this space group. Using first principles computations, we have fully determined the lattice constants a and c, as well as 10 internal parameters that define this unique structure of primitive unit cells of 40 atoms. For β-In2S3 our computed values are found to be consistent with experimental measurements. The bulk modulus B, local electronic density of states, total density of states, and band gap Eg of these phases have been investigated.