DFT Insight into The Optoelectronic Potential of XMgBr3 (X= Cs, K, Rb) Halide Perovskites

Due to their appropriate band gaps, structure stability, and abundance on earth and low toxicity, halide perovskites have gained much interest as promising materials in optoelectronics in a broad application. In the paper, the structural, elastic, electronic, mechanical and optical properties of XMgBr ₃ (X = Cs, K, Rb) halide perovskites are thoroughly studied using the framework of the density functional theory (DFT). To investigated the electronic properties to obtain the correct estimation of the band-gap PBE-GGA, TB-mBJ and HSE06 potentials were applied. In addition, optical analysis of the response of their systems is performed on the basis of the dielectric function, refractive index, reflectivity, optical conductivity, and absorption coefficient in a broad photon-energy spectrum. The obtained the elastic constants and the mechanical parameters obtained prove that these materials are mechanically stable, ductile, and possess rather low stiffness. The findings indicate desirable optoelectronic properties, which tends to support the use of XMgBr ₃ (X = Cs, K, Rb) halide perovskites in high-technological electronic and optoelectronic systems. The experimental results are an excellent theoretical contribution to the experimental investigation and instrumentation in the future.