Inorganic CsPbI₃ perovskite quantum dots (PQDs) possess remarkable optical properties, making them highly promising for photovoltaic applications. However, the inadequate stability resulting from internal structural instability and the complex external surface chemical environment of CsPbI₃ PQDs has hindered the development of CsPbI₃ PQD solar cells (PQDSCs). In this work, the capping layer composed of inorganic two-dimensional (2D) Ruddlesden–Popper (RP) phase Cs₂PbI₂Cl₂ nanosheets (NSs) is introduced, which may be effectively treated to improve the surface properties of the CsPbI₃ PQD film. This modification serves to passivate defects by filling cesium and iodine vacancies while optimizing the energy band arrangement and preventing humidity intrusion, leading to the meliorative stability and photovoltaic performance. The optimized CsPbI₃ PQDSCs achieve an enhanced power conversion efficiency (PCE) of 14.73%, with the superb stability of only a 16% efficiency loss after being exposed to ambient conditions (30 ± 5% RH) for 432 h.

中文翻译：

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二维 Cs2PbI2Cl2 纳米片钝化用于高效稳定的 CsPbI3 量子点太阳能电池

无机CsPbI ₃钙钛矿量子点（PQD）具有卓越的光学特性，使其在光伏应用中极具前景。然而，CsPbI ₃ PQDs内部结构不稳定和复杂的外表面化学环境导致稳定性不足，阻碍了CsPbI ₃ PQD太阳能电池（PQDSC）的发展。在这项工作中，引入了由无机二维（2D）Ruddlesden-Popper（RP）相Cs ₂ PbI ₂ Cl ₂纳米片（NSs）组成的覆盖层，可以对其进行有效处理以改善CsPbI ₃的表面性能。 PQD 薄膜。这种修饰通过填充铯和碘空位来钝化缺陷，同时优化能带排列并防止湿气侵入，从而改善稳定性和光伏性能。优化的 CsPbI ₃ PQDSC 实现了 14.73% 的增强功率转换效率 (PCE)，并且在暴露于环境条件 (30 ± 5% RH) 432 小时后，效率仅损失 16%，具有出色的稳定性。