Study of physical properties of the new inorganic perovskites LiSnX₃ (X=Br or I): A DFT approach

Abstract

This work aims to study the optoelectronic and thermoelectric properties of the new perovskites LiSnX 3 (X[Formula: see text]Br or I). This study is carried out by using the density functional theory (DFT) combined with the Boltzmann transport theory. First, the investigation of the structural, electronic and optical properties of such materials, using the Generalized Gradient Approximation (GGA), has been performed. This latter method has been performed under the Perdew–Burke–Ernzerhof (GGA–PBE) approximation applying the exchange correlation potential. It is found that the two compounds exhibit a p-type semiconductor characteristic and interesting optical properties. Moreover, the thermoelectric properties of the studied materials, such as the Seebeck coefficient, electrical conductivity, thermal conductivity, figure of merit and power factor, have been examined. It is found that the Seebeck coefficient takes positive values. This finding reveals and confirms the p-type semiconductor characteristic for two studied compounds. On the other hand, such materials display large values of the figure of merit (ZT) in comparison with the existing thermoelectric materials. Such large values of ZT are found for both small or large temperature values. The obtained results of the optoelectronic and thermoelectric properties show that these materials could be useful both for photovoltaic and thermoelectric applications.