A novel strategy for discovering inorganic solar-cell absorbers: leveraging octahedral features in ABX3 structures

Abstract

Recently, inorganic perovskite solar cells have been extensively studied to overcome the stability challenges of organic–inorganic hybrid perovskites (OIHPs). However, achieving both high photovoltaic performance and long-term stability using fully inorganic perovskite absorbers remains a challenge. In this study, we systematically screened all known octahedral ABX₃ inorganic compounds from crystal structure databases using high-throughput first-principles calculations. Our results show that the screened materials align well with previously identified promising materials and also identify several chalcogenides with low-symmetry octahedral structures as potential candidates for new photovoltaic materials. Furthermore, we quantified structural characteristics of the octahedral framework, such as octahedral interconnections, regularities of individual octahedra, and the spatial locations of residual valence states of cations (RVSC). By analyzing the distribution of photovoltaic properties in relation to these structural parameters, we found that chalcogenides are much more tolerant to structural deviations compared to halides and that RVSC within octahedral units contributes to lighter hole effective masses. With these insights, we propose a perovskite-inspired strategy for discovering novel solar cell absorbers.