Tailoring RP-structured two-dimensional perovskite with controlled interlayer distance

Organic–inorganic metal halide perovskites have garnered significant attention as next-generation materials due to their exceptional optoelectronic properties. However, their commercialization is hindered by their inherent instability, as they are highly susceptible to external factors such as light, heat, and humidity. To overcome these limitations, various engineering strategies have been explored. Among them, two-dimensional (2D) perovskites have been widely adopted due to their enhanced stability and relatively simple fabrication processes. Despite their promising applications, fundamental research on 2D perovskites remains limited. In this study, we investigate the electronic structure and optical properties, such as bandgap and exciton binding energy of 2D perovskites, by modulating their interlayer distance through cation size variation. We demonstrate that structural modifications induced by the length of organic cations significantly influence charge transport within the 2D perovskite framework, thereby affecting charge carrier mobility. Our analysis of the property variations resulting from interlayer distance control provides fundamental insights into the potential applications of 2D perovskites in optoelectronic and energy-related devices.