Effect of S, Se and Te replacement on structural, optoelectronic and transport properties of SrXO4 (X= S, Se, Te) for energy applications: A first principles study

Abstract

Optoelectronic and thermoelectric properties of SrXO 4 (X ​= ​S, Se, Te) have been investigated with the help of WIEN2K code by using FP-LAPW method and GGA approximation of the DFT approach. The obtained results show that SrSO 4 and SrSeO 4 are direct wide band gap semiconductors, while, SrTeO 4 is an indirect band gap semiconductor. Based on theoretical study of optical properties, it has been established that the investigated compounds are promising candidates for active optical devices operating in the UV and visible range. These compounds have also been found to be weak reflectors for incident photons as they reflect up to 60% of the incident photons in the upper UV region. The semi-classical Boltzmann transport kinetic equations are used to study thermoelectric properties such as electrical conductivity, thermal conductivity, power factor, Seebeck coefficient and Figure of merit of the considered compounds. The research shows that SrSeO 4 and SrTeO 4 are promising compounds for thermoelectric devices. • Optoelectronic and thermoelectric properties of SrXO 4 (X ​= ​S, Se, Te) have been investigated with the help of WIEN2K code by using FP-LAPW (full potential linear augmented plane wave) method and GGA approximation. • Calculations show that NbCu 3 Se 4 and TaCu 3 Se 4 are semiconductor compounds. • Investigated results show that SrSO 4 [3.264 ​eV]/SrSeO 4 [3.621 ​eV] are direct band gap semiconductors, however, SrTeO 4 [2.236 ​eV] is indirect band gap semiconductor. • The compounds are week reflectors of incident photons as they reflect maximum of 60% incident photons in upper UV region.