Hybrid perovskites are currently one of the most active fields of research owing to their enormous potential for photovoltaics. The performance of 3D hybrid organic–inorganic perovskite solar cells has increased at an incredible rate, reaching power conversion efficiencies comparable to those of many established technologies. However, the commercial application of 3D hybrid perovskites is inhibited by their poor stability. Relative to 3D hybrid perovskites, low-dimensional — that is, 2D — hybrid perovskites have demonstrated higher moisture stability, offering new approaches to stabilizing perovskite-based photovoltaic devices. Furthermore, 2D hybrid perovskites have versatile structures, enabling the fine-tuning of their optoelectronic properties through compositional engineering. In this Review, we discuss the state of the art in 2D perovskites, providing an overview of structural and materials engineering aspects and optical and photophysical properties. Moreover, we discuss recent developments along with the main limitations of 3D perovskites and assess the advantages of 2D perovskites over their 3D parent structures in terms of stability. Finally, we review recent achievements in combining 3D and 2D perovskites as an approach to simultaneously boost device efficiency and stability, paving the way for mixed-dimensional perovskite solar cells for commercial applications.

混合钙钛矿由于其在光伏领域的巨大潜力，目前是最活跃的研究领域之一。3D混合有机-无机钙钛矿太阳能电池的性能以惊人的速度提高，达到了许多现有技术可比的功率转换效率。但是，3D杂化钙钛矿的商业应用受到其较差的稳定性的抑制。相对于3D混合钙钛矿，低维（即2D）混合钙钛矿表现出更高的水分稳定性，为稳定基于钙钛矿的光伏器件提供了新方法。此外，二维杂化钙钛矿具有通用结构，可通过成分工程对其光电特性进行微调。在这篇评论中，我们讨论了2D钙钛矿的最新技术，提供结构和材料工程方面以及光学和光物理性质的概述。此外，我们讨论了3D钙钛矿的最新发展以及主要局限性，并在稳定性方面评估了2D钙钛矿相对于3D母体结构的优势。最后，我们回顾了结合3D和2D钙钛矿作为同时提高设备效率和稳定性的方法所取得的最新成就，为混合尺寸的钙钛矿太阳能电池为商业应用铺平了道路。