Ruddlesden–Popper Perovskite for Stable Solar Cells

Three‐dimensional metal‐halide perovskites have emerged as promising light harvesting materials for converting sunlight to electricity in the last few years. High power conversion efficiency of 23.3% has been demonstrated. However, the main challenge that currently limits the application of the perovskite solar cells is the long‐term stability, which has ambient, thermal, and photo stability weaknesses. Recently, the quasi two‐dimensional Ruddlesden–Popper perovskites have showed great potential to enhance the stability and achieved an acceptable power conversion efficiency (>13%) compared to the traditional three‐dimensional perovskites. The long organic cations in low‐dimensional perovskites are more hydrophobic than the typically used short methylammonium cation in three‐dimensional perovskites. Here, we summarize recent developments of the Ruddlesden–Popper perovskite solar cells, including Lead‐based quasi two‐dimensional and Lead‐free quasi two‐dimensional perovskite structure. The light harvesting performance and charge‐carrier dynamics in these perovskite solar cells are reviewed. In addition, critical challenges that limit the performance of Ruddlesden–Popper perovskite solar cells are discussed. Perspectives and future directions are proposed.