Organic Molecules in All‐Inorganic CsPbI x Br3−x Perovskite Solar Cells: Interface Modifiers or Precursor Additives

Due to their excellent thermal stability and suitable bandgap, all‐inorganic CsPbI x Br3−x perovskite solar cells (PSCs) have attracted extensive attention in the photovoltaic field. However, iodine vacancies and undercoordinated Pb2+ lead to serious nonradiative recombination losses on the surface of CsPbI x Br3−x perovskite film, resulting in lower open‐circuit voltage. At the same time, the cubic phase (α phase) tends to transform into the yellow phase (δ phase) with nonphotoactive in an environment of higher humidity and lower temperature, which limits its further commercial development. In order to solve the above problems, a lot of research work is focused on interface modification and precursors doping to improve the crystallinity, surface hydrophobicity, and phase stability of perovskite films. In this review, the application of organic molecules in all‐inorganic CsPbI x Br3−x PSCs and prospected the research direction in the future to further improve the performance and stability are summarized. The organic molecules are employed to passivate defects, release micro‐strain, inhibit phase transition, suppress halide segregation, promote carrier transport, and enhance hydrophobicity. This review gives an insightful overview of recent progress in organic molecules into all‐inorganic CsPbI x Br3−x perovskite solar cells as interface modifiers and precursor additives. Moreover, a perspective on challenges and opportunities is proposed in the field.