DFT-based computational investigations of structural, mechanical, optoelectronics, and thermoelectric properties of InXF3 (X = Be and Sr) ternary fluoroperovskites compounds

Abstract

Wide-band gap semiconductors are very interesting due to their high frequency applications. Perovskite have proved to be most stable structures useful for many applications e.g. solar cells detectors etc The current work is based on the prediction of two new materials (InXF3 where X = Be and Sr) for the use of high energy applications. The modelling and simulations were performed through the WIEN2K and BoltzTrap2 packages. The most accurate and precise exchange-correlation of TB-mBJ potential interfaced within WIEN2K is utilized for obtaining better results. The results showed that the selected compounds possess a cubic crystal structure with a space group of Pm-3m (#221). The Goldschmidt’s tolerance factor (τ) is determined and is found to be 0.96 for InBeF3 and 0.92 for InSrF3 which indicates the stability of the compounds in cubic phase. The unit cell crystal structural optimization is done to evaluate the ground state lattice parameters. Both the compounds possess a semiconducting nature having an indirect band gap of 3.06 eV for InBeF3 from M-X symmetry points while a direct band gap from X-X of 3.98 eV for InSrF3 compound. The optical properties are computed and analyzed from the optical dielectric function for both the compounds within the energy range of 0 eV to 40 eV and the results depict that these materials are more sensitive at higher energy range, possess high absorption and optical conductivity in good agreement with electronic band structure. Mechanically these compounds are stable, ductile, anisotropic, and hard to scratch. The thermoelectric properties are evaluated for InXF3 (X = Be and Sr) compounds up to a temperature range of 1000 K. This work can open new opportunities for further exploration in this field.