Ion Transport in Two-Dimensional Hybrid Organic-Inorganic Perovskite

Abstract

Hybrid organic-inorganic perovskites (HOIPs) are a promising materials platform for solar cells as well as a plethora of other photovoltaic applications due to their high cell efficiency, low production costs, and bandgap tunability. However, the commercialization of perovskite solar cells is currently limited by their operational lifetimes, which are short due to the sensitivity of perovskites towards moisture, oxygen, light and elevated heat. One major cause of this instability is the prevalence of ionic defects that lead to permanent device degradation at the solar cell layer interface. The development of passivation strategies to reduce film defects are thus crucial for the continued advancement in perovskite technology. In this study, we investigate a potential material for passivation – 2D HOIPs, which have been hypothesized to increase solar cell stability by inhibiting ionic transport due to its organic layer. We explore the effect of ligand properties on ion transport through novel 2D HOIPs via a systematic computational-experimental approach. By understanding how structural and chemical characteristics like bulkiness and electronegativity in organic ligands affect halide diffusion in 2D HOIPs, we begin to understand the parameters for designing effective passivation materials for stable and efficient perovskite solar cells.