Advancing Structural and Mechanical Stability of Organic-Inorganic Perovskite Solar Cells: A DFT Study

This work presents a first-principles density functional theory (DFT) investigation of 27 ABX₃ metal halide perovskite compositions to establish fundamental structure–property relationships governing their stability. By systematically varying the A-site (Cs⁺, MA⁺, FA⁺), B-site (Ge²⁺, Sn²⁺, Pb²⁺), and X-site (Cl⁻, Br⁻, I⁻) constituents, the study examines the influence of chemical composition on structural, energetic, thermodynamical and mechanical properties. Particular emphasis is placed on understanding how local octahedral distortions and chemical bonding determine structural and energetic stability, and elastic behavior. The results provide atomistic insights into the role of composition in controlling the properties of inorganic and hybrid perovskites, offering theoretical guidelines for the rational design of stable and high-performance functional materials for solar cell applications.