Perovskite solar cells (PSCs) have rapidly emerged as one of the hottest topics in the photovoltaics community owing to their high power-conversion efficiencies (PCE), and the promise to be produced at low cost. Among various PSCs, typical 3D perovskite-based solar cells deliver high PCE but they suffer from severe instability, which restricts their practical applications. In contrast to 3D perovskites, 2D perovskites that incorporate larger, less volatile, and generally more hydrophobic organic cations exhibit much improved thermal, chemical, and environmental stability. 2D perovskites can have different roles within a solar cell, either as the primary light absorber (2D PSCs), or as a capping layer atop a 3D perovskite absorbing layer (2D/3D PSCs). Tradeoffs between PCE and stability exist in both types of PSCs—2D PSCs are more stable but exhibit lower efficiency while 2D/3D PSCs deliver exciting efficiency but show relatively poor stability. To address this PCE/stability tradeoff, the challenges both the 2D and 2D/3D PSCs face are identified and select works the community has undertaken to overcome them are highlighted in this review. It is ended with several recommendations on how to further improve PSCs so their performance and stability can be commensurate with application requirements.

中文翻译：

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为高效稳定的太阳能电池推进二维钙钛矿：挑战与机遇

钙钛矿太阳能电池 (PSC) 因其高功率转换效率 (PCE) 和低成本生产的前景而迅速成为光伏界最热门的话题之一。在各种 PSC 中，典型的 3D 钙钛矿基太阳能电池具有较高的 PCE，但它们存在严重的不稳定性，这限制了它们的实际应用。与 3D 钙钛矿相比，2D 钙钛矿包含更大、挥发性更低且通常更疏水的有机阳离子，其热稳定性、化学稳定性和环境稳定性显着提高。2D 钙钛矿在太阳能电池中可以发挥不同的作用，既可以作为主要光吸收剂 (2D PSC)，也可以作为 3D 钙钛矿吸收层 (2D/3D PSC) 上的覆盖层。两种类型的 PSC 都存在 PCE 和稳定性之间的权衡——2D PSC 更稳定但效率较低，而 2D/3D PSC 提供令人兴奋的效率但稳定性相对较差。为了解决这种 PCE/稳定性折衷，2D 和 2D/3D PSC 面临的挑战被确定，并在本次审查中强调了社区为克服这些挑战而开展的工作。最后提出了一些关于如何进一步改进 PSC 以使其性能和稳定性与应用要求相称的建议。