Two dimensional (2D) perovskite materials, are more stable than 3D perovskite materials, which could solve the stability issue of perovskite solar cells (PSCs). However, the photovoltaic conversion efficiency (PCE) of PSCs based on 2D perovskite materials was low, due to the high dielectric and quantum confinement of 2D perovskite. In this work, we propose a solvent-assisted method to prepare 2D perovskite films, where the solvent was distributed in a gradient. Therefore, the top-down crystallization process of 2D perovskite can be accurately controlled. The PCE of PSCs fabricated by the solvent-assisted method was enhanced by 48%, compared with the control device. For the packaged devices, the stability test demonstrated that 94% of the initial PCE was still maintained after 1500 hours of storage (25 °C, RH 40%). After carefully analyzing the photophysical process of the carriers in the PSCs based on 2D perovskite, the enhanced carrier transfer mechanism of the solvent-assisted method has been proposed.

中文翻译：

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二维 Ruddlesden-Popper 钙钛矿的溶剂辅助结晶

二维 (2D) 钙钛矿材料比 3D 钙钛矿材料更稳定，可以解决钙钛矿太阳能电池 (PSC) 的稳定性问题。然而，由于二维钙钛矿的高介电和量子限制，基于二维钙钛矿材料的 PSC 的光伏转换效率 (PCE) 较低。在这项工作中，我们提出了一种溶剂辅助方法来制备二维钙钛矿薄膜，其中溶剂以梯度分布。因此，可以精确控制二维钙钛矿的自上而下结晶过程。与对照装置相比，通过溶剂辅助方法制造的 PSC 的 PCE 提高了 48%。对于封装的器件，稳定性测试表明，在储存 1500 小时（25°C，相对湿度 40%）后，初始 PCE 的 94% 仍保持不变。