Comparative analysis of inorganic lead halide perovskites with promising (Mg⁺²)-doped for optoelectronic applications: a computational insights

This paper presents a comprehensive analysis of the crystal structure, electronic characteristicsmechanical and optical responses of CsPbBr_3, CsPbCl_3, CsPbI₃ and Mg⁺²-doped at the Pb⁺²-site perovskites. Our investigation is based on density functional theory calculations, shedding light on their potential applications in solar cells. Moreover, they exhibit characteristics of a direct bandgap nature, with computed bandgap values of 1.61 eV (CsPbI₃), 1.58 eV (0.25 Mg⁺²), 1.49 eV (0.50 Mg⁺²), 1.28 eV (0.75 Mg⁺²) for the first material; 1.86 eV (CsPbBr₃), 1.55 eV (0.25 Mg⁺²), 1.09 eV (0.50 Mg⁺²), 0.94 eV (0.75 Mg⁺²) for the second material; and 2.28 eV (CsPbCl₃), 2.34 eV (0.25 Mg⁺²), 2.27 eV (0.50 Mg⁺²), and 3.52 eV (0.75 Mg⁺²) for the third material, respectively. Notably, these compounds display characteristics of direct bandgap behavior. The valence band maximum is primarily derived from halide p orbitals, forming hybrid states with Pb-5s states. It is discerned that alterations in the lattice parameter and volume of the pure and doped CsPb_1 − xMg_xl₃, CsPb_1 − xMg_xBr₃, and CsPb_1 − xMg_xCl₃ materials unit cell lead to proportional modifications in the band gap values. The achieved results show that the systems can exist stably in terms of mechanical as well as dynamical stabilities, and CsPb_1 − xMg_xl₃, CsPb_1 − xMg_xBr₃, and CsPb_1 − xMg_xCl₃ (0, 0.25, 0.50, and 0.75) materials structures have anisotropy and ductile elastic responses. These materials exhibit excellent photon absorption capabilities owing to their narrow bandgaps, as evidenced by their distinctive optical properties. The real (ε₁ (ω)) and imaginary (ε₂ (ω)) components of their dielectric functions indicate a remarkable capacity to effectively capture and retain absorbed energy. Specifically, in the case of pure and doped CsPb_1 − xMg_xl₃, CsPb_1 − xMg_xBr₃, and CsPb_1 − xMg_xCl₃, these characteristics make them highly promising for utilization in solar cells and energy storage applications. It is remarkable to report that, notably, at elevated photon energy levels, these materials also display super luminescent behavior, thus further expanding their potential for advanced optoelectronic applications.