CsTiI (CsTiIBr) Halide Perovskite Solar Cell and Its Point Defect Analysis.

This work presents a comprehensive numerical study for designing a lead-free, all-inorganic, and high-performance solar cell based on CsTiI halide perovskite with all-inorganic carrier transport layers. A rigorous ab initio density-functional theory (DFT) calculation is performed to identify the electronic and optical properties of CsTiI and, upon extraction of the existing experimental data of the material, the cell is designed and optimized to the degree of practical feasibility. Consequently, a theoretical power conversion efficiency (PCE) of 21.