Structured Perovskite Light Absorbers for Efficient and Stable Photovoltaics

Abstract Organic–inorganic hybrid lead‐halide perovskite materials (ABX 3 ) have attracted widespread attention in the field of photovoltaics owing to their impressive optical and electrical properties. However, obstacles still exist in the commercialization of perovskite photovoltaics, such as poor stability, hysteresis, and human toxicity. A‐site cation engineering is considered to be a powerful tool to tune perovskite structures and the resulting optoelectronic properties. Based on the selection and combination of A‐site cations, three types of perovskite structures, i.e., 3D perovskite, reduced‐dimensional (2D/quasi‐2D) perovskite, and 2D/3D hybrid perovskite can be formed. Herein, the remarkable breakthroughs resulting from these three perovskite structures are summarized, and their corresponding properties and characteristics, as well as their intrinsic disadvantages, are highlighted. By summarizing recent research progress, a new viewpoint for improving the performance and stability of perovskite photovoltaics is provided.