DFT study of structural, mechanical, and opto-electronic properties of scadium-based halide double perovskite Cs2ScInBr6 for optoelectronic applications

Abstract

A complete and compressive first-principles investigation of the physical characteristics of a lead-free halide double perovskites Cs2ScInBr6, has been reported. Cs2ScInBr6 has a small and direct bandgap at L-point, as predicted from the band structure profile. The band structure were calculated using GGA and GGA + mBJ potential and it shows the same trend in both exchange-correlation potential. The calculated value of bandgap using GGA potential is 0.73 eV, while using mBJ it has 0.81 eV. The lattice stability reported in this study was in good agreement with previously synthesised, and analyzed double perovskites Cs2AgBiBr6. Similarly, from elastic analysis results show that the material under investigation is mechanically stable, and ductile in nature. Optical properties like absorption coefficients, refractive index, optical conductivity and reflectivity, electron energy loss, and extinction coefficients are computed and studied over an energy range of 0–4 eV. The analysis of small and direct band gaps, as well as optical properties such as absorption coefficients, show that Cs2ScInBr6 is suitable for infrared device applications. Also, the findings of current study would be useful for future experimental investigations to assess Cs2ScInBr6 for optoelectronic applications.