Experimental and theoretical study of the electronic energy structure of phosphorus containing sulfides InPS4, Tl3PS4 and Sn2P2S6

The electronic energy structures of three phosphorus-containing sulfides are studied from the experimental K and L 2,3 X-ray emission spectra, K absorption spectra of sulfur and phosphorus, X-ray photoelectron spectra, and also quantum chemical calculations based on density functional theory (DFT). The fullpotential and all-electron quantum chemical calculations are carried out using the LAPW+lo basis set implemented in the WIEN2k software package [1]. The following exchange-correlation potentials are used for the calculations: PBE, PBE+U, and mBJ [2]. The spin-orbit coupling of Tl 5 d 3/2 and 5 d 5/2 electronic states are taken into account in Tl 3 PS 4 . All the specific features of the electronic energy structures of the compounds under study are determined in the valence and conduction bands near the Fermi level. The obtained band gaps E g are in good agreement with the literature experimental data.