Zahra Bayhan, Shabir Ali, Abdullah Almohammedi, Ali El-Rayyes, Hafeez Ur Rehman
In this study, First-principles calculations were conducted to investigate the structure, electric, optical, and thermodynamic properties of Sr-minerals based halide perovskites, in order to gain insight into their potential for optoelectronic applications. The present work aims to comprehensively investigated the structural, electronic, elastic and optical properties of Sr-minerals based halide perovskites of XSrBr3 (X = Cs, Rb, and K) through first principles density functional theory (DFT)-based calculations. The PBE-GGA, TB-mBJ and HSE06 exchange-correlation schemes were used to calculate the electronic band structures of XSrBr3 (X = Cs, Rb, K) to obtain better reliability in the prediction of the band-gap energies. CsSrBr3 was found to have indirect band gaps of (4.249, 6.351 and 5.333) eV with the PBE-GGA, TB-mBJ, and HSE06 methods, respectively. The values of the corresponding band gaps for RbSrBr3 were (3.932, 6.421 and 5.023) eV, while KSrBr3 had indirect gaps of (3.797, 6.642 and 4.860) eV, respectively. Based on the result obtained, that all the three compounds are semiconducting with high band gap. The optical properties show a high absorption in the UV region, and good refractive-index and dielectric responses, particularly for XSrBr3 (X = Cs, Rb, K) for optoelectronic applications in the UV region. All these compounds are mechanically stable and ductile as the calculated elastic constants meet all mechanical stability requirements. They have relatively low moduli of elasticity indicating moderate rigidity, and perhaps better mechanical processability. The finding of these characteristics makes CsSrBr3, RbSrBr3 and KSrBr3 interesting for application as UV photodetectors, as optoelectronic devices resistant to radiation, and as electronic devices with a wide band gap.