Progress of 2D Perovskite Solar Cells: Structure and Performance

2D perovskite has demonstrated great potential for application in photovoltaic devices due to the tunable energy bands, suppressed ion migration, and high stability. However, 2D perovskite solar cells (PSCs) display suboptimal efficiency in comparison to 3D perovskite solar cells, which can be attributed to the quantum confinement and dielectric confinement effects resulting from the intercalation of organic spacer cations into the perovskite lattice. This review starts with the fundamental structural characteristics, optoelectronic properties, and carrier transport dynamics of 2D PSCs, followed by the discussion of approaches to improve the photovoltaic performance of 2D PSCs, including the manipulation of crystal orientation, phase distribution, pure phase, organic layer, and device engineering. Then the advancements in the structural, humidity, thermal, and maximum power point tracking stability of 2D PSCs are summarized. Afterward, the applications of 2D perovskite in 2/3D PSCs to improve efficiency and stability are discussed. This review provides a comprehensive understanding of the relationship between 2D perovskite structure and the performance of the resulting 2D PSCs, as well as offers insights for constructing efficient and stable 2/3D PSCs by integrating 2D and 3D perovskites.