Electronic, optical, and thermoelectric properties of perovskite BaTiO3 compound under the effect of compressive strain

The theoretical effects of compressive strain on electronic, optical and thermoelectric properties for the cubic and tetragonal phases of BTO perovskite-type crystal have been investigated using Density Functional Theory (DFT). It was found that the compressive strain influences on the nature of the forbidden band of the cubic and tetragonal phases of BTO because by applying −2.3% or more of compressive strain, BTO becomes a semiconductor with a direct forbidden gap which eliminate the additional interaction in the CB which is a quite remarkable for photovoltaic devices. Furthermore, the values of forbidden gap width increase with increasing the percentage of compressive strain which shows the piezoelectric property of BTO. Moreover, the optical properties show that the pure and compressed BTO compounds are good materials for optical applications in both visible and UV spectrum. Additionally, the mobility of the holes grows with the compressive strain, which leads to increase the thermal and electrical conductivity of BTO.