Surface imperfections created during fabrication of halide perovskite (HP) films could induce formation of various defect sites that affect device performance and stability. In this work, all‐organic surface modifiers consisting of alkylammonium cations and alkanoate anions are introduced on top of the HP layer to passivate interfacial vacancies and improve moisture tolerance. Passivation using alkylammonium alkanoate does not induce formation of low‐dimensional perovskites species. Instead, the organic species only passivate the perovskite's surface and grain boundaries, which results in enhanced hydrophobic character of the HP films. In terms of photovoltaic application, passivation with alkylammonium alkanoate allows significant reduction in recombination losses and enhancement of open‐circuit voltage. Alongside unchanged short‐circuit current density, power conversion efficiencies of more than 18.5 % can be obtained from the treated sample. Furthermore, the unencapsulated device retains 85 % of its initial PCE upon treatment, whereas the standard 3D perovskite device loses 50 % of its original PCE when both are subjected to ambient environment over 1500 h.

中文翻译：

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全有机层间表面改性剂对钙钛矿太阳能电池效率和稳定性的影响

卤化钙钛矿（HP）薄膜制造过程中产生的表面缺陷可能导致形成影响器件性能和稳定性的各种缺陷部位。在这项工作中，由烷基铵阳离子和链烷酸根阴离子组成的全有机表面改性剂被引入到HP层的顶部，以钝化界面空位并提高耐湿性。使用链烷酸烷基铵钝化不会诱导形成低维钙钛矿物种。相反，有机物仅钝化钙钛矿的表面和晶界，这导致HP膜的疏水性增强。在光伏应用方面，用链烷酸烷基铵钝化可显着降低复合损失并提高开路电压。除不变的短路电流密度外，从处理后的样品中可以获得超过18.5％的功率转换效率。此外，经过处理的未封装设备保留了其初始PCE的85％，而当标准3D钙钛矿设备都在1500 h内经受环境测试时，其原始PCE损失了50％。