Unveiling the optical and piezoelectric properties of organic-inorganic hybrid perovskites FAPbX3 (X = Cl, Br, I): A DFT study

Abstract

This work encloses the investigation of the optical and piezoelectric properties of FAPbX3(X = Cl, Br, I) by employing the Density Functional Theory(DFT). Our results reveal that all the compounds are semiconductor in nature. The material’s thermodynamical stability was validated by using formation energy calculation, where FAPbCl3 was found to be the most stable among the investigated compounds. Each substitution along the X-site atom leads to an increase in volume with decrease in band gap due to increase in the atomic radii of the halogen atom. The optical properties such as dielectric functions, refractive index, extinction coefficient, reflectivity and absorption coefficient were explored, showing promising properties for an optoelectronic device. Each compound’s mechanical stability are validated using Born criteria. Among the studied compounds, FAPbCl3 stands out to be the most efficient towards piezoelectric application with a maximum response of e33=-1.55 C/m2. Overall, the investigated compounds are a feasible candidate for optoelectronic and piezoelectric device fabrication due to their prospective optical and piezoelectric properties.