Screening the geometrical, thermodynamic, mechanical, and bond population characteristics of inorganic halide perovskites AgSrX3 (X=Cl, Br, I) for photovoltaic applications: A DFT insight

Abstract

Halide perovskites have gained significant focus in diverse fields because of their flexible chemistry and remarkable ionic conductivity. Herein, the geometrical, electronic, mechanical, thermodynamic, and bond population characteristics of AgSrX₃ (X = Cl, Br, and I) inorganic halide perovskites were investigated using DFT within CASTEP framework by considering HSE03 functional. Structural optimization reveals well-defined cubic symmetry with space group Pm-3m [221], and negative formation energy values confirmed their thermodynamic stability. The calculated band gaps are 2.81 eV for AgSrCl₃, 2.14 eV for AgSrBr₃, and 1.21 eV for AgSrI₃, indicating their semiconductor behavior. DOS reveals that valence bands are primarily influenced by the Ag-d orbitals and p orbitals of the halide’s ions. The elastic constants (C₁₁, C₁₂, and C₄₄) satisfy the Born stability criteria, confirmed their mechanical stability. The results of the derived bulk (B), shear (G), and Young’s (Y) moduli, along with Poisson’s ratios (ν) illustrates the ductile character. Furthermore, bond population, Mulliken, and Hirshfeld charges analyses indicating more localized electron density, with Mulliken predicts higher partial charges. Confidently, these AgSrX₃ (X = Cl, Br, and I) halide perovskites have promising feasibility for advanced photovoltaic applications.