A DFT insight into the physical features of alkaline based perovskite compounds AInBr3 (A = K, Rb)

Owing to their proper characteristic, simple halide perovskites became engaged over time for thermoelectric applications. In this work, several physical properties of simple halide perovskite materials AInBr3 (A = K, Rb) are predicted based on density functional theory (DFT) within the Wien2k code. The tolerance factor and negative formation energy demonstrate the stability and formation of these compounds, and the Born criteria shows their mechanical stability and inherent ductility. Notably, the modified Becke-Johnson potential (mBJ) was used to calculate the optoelectronic characteristics. The AInBr3 (A = K, Rb) perovskites present semiconducting aspects. Analyses of their optical characteristics, including refractive index, reflectivity, were performed. AInBr3 (A = K, Rb) transport properties were studied. The highest figure of merit was attained by AInBr3 (A = K, Rb) which had a high Seebeck coefficient and high electrical conductivity. Finally, all studied properties of simple halide perovskites give a new way for efficient applications in thermoelectric.