Improved Power Conversion Efficiency with Tunable Electronic Structures of the Cation-Engineered [A_i]PbI₃ Perovskites for Solar Cells: First-Principles Calculations

Higher power conversion efficiencies for photovoltaic devices can be achieved through simple and low production cost processing of (Formula presented.) perovskites. Due to their limited long-term stability, however, there is an urgent need to find alternative structural combinations for this family of materials. In this study, we propose to investigate the prospects of cation-substitution within the A-site of the (Formula presented.) perovskite by selecting nine substituting organic and inorganic cations to enhance the stability of the material. The tolerance and the octahedral factors are calculated and reported as two of the most critical geometrical features, in order to assess which perovskite compounds can be experimentally designed. Our results showed an improvement in the thermal stability of the organic cation substitutions in contrast to the inorganic cations, with an increase in the power conversion efficiency of the Hydroxyl-ammonium (NH₃OH) substitute to η = 25.84%.