Metal halide perovskites having three-dimensional crystal structures have already been applied successfully in various optoelectronic applications. To address their most challenging issues-instability and toxicity-without losing efficiency, lower-dimensional perovskites appear to be promising alternatives. Recently, two-dimensional (2D) perovskite solar cells have been developed exhibiting excellent photostability and moisture stability, together with moderate device efficiency. This Review summarizes the photophysical properties and operating mechanisms of 2D perovskites as well as recent advances in their applications in solar cell devices. Also presented is an agenda for the next-stage development of stable perovskite materials for solar cell applications, highlighting the issues of stability and toxicity that require further study to ensure commercialization.

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层状钙钛矿材料：高效稳定钙钛矿太阳能电池的关键解决方案

具有三维晶体结构的金属卤化物钙钛矿已成功应用于各种光电应用。为了解决它们最具挑战性的问题——不稳定性和毒性——而不损失效率，低维钙钛矿似乎是有希望的替代品。最近，已经开发出二维（2D）钙钛矿太阳能电池，表现出优异的光稳定性和水分稳定性，以及适中的器件效率。本综述总结了二维钙钛矿的光物理性质和运行机制，以及它们在太阳能电池器件中的应用的最新进展。还提出了下一阶段开发用于太阳能电池应用的稳定钙钛矿材料的议程，