Surface defect passivation through additional molecular bonding plays a crucial role in optimization of perovskite-based photovoltaic devices. So far, quantization of the defect site coverage by molecular passivation remains unclear from a macroscopic view. We herein unravel the coverage possibility of the surface defect sites of perovskite films by the added molecule passivators upon an MAPbI₃ perovskite system. Concerns of inconsistent time-resolved photoluminescence (TRPL) spectroscopic measurements are dispelled by vapor-deposition fabrications of highly uniform perovskite films. The surface defect densities of perovskite films are derived from global fittings of the charge carrier dynamics to the measured TRPL decays. It is revealed the Langmuir adsorption relationship of the defect site coverage with respect to the added amount of tri-n-octylphosphine oxide passivation molecules. Our work supplements the dynamical bonding model of the molecular passivation process and provides reliable knowledge upon the bonding process between molecules and defects, which leads to rationalized surface passivation methodologies in perovskite photovoltaics communities.

中文翻译：

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MAPbI3钙钛矿薄膜的分子钝化遵循朗缪尔吸附规则

通过额外的分子键实现表面缺陷钝化在钙钛矿基光伏器件的优化中起着至关重要的作用。到目前为止，从宏观角度来看，分子钝化对缺陷位点覆盖的量化仍然不清楚。我们在此揭示了在 MAPbI _{3 上}添加分子钝化剂对钙钛矿薄膜表面缺陷位点的覆盖可能性钙钛矿系统。高度均匀的钙钛矿薄膜的气相沉积制造消除了对时间分辨光致发光 (TRPL) 光谱测量不一致的担忧。钙钛矿薄膜的表面缺陷密度来自电荷载流子动力学与测量的 TRPL 衰减的全局拟合。揭示了缺陷位点覆盖率与三正辛基氧化膦钝化分子添加量的朗缪尔吸附关系。我们的工作补充了分子钝化过程的动态键合模型，并提供了有关分子与缺陷之间键合过程的可靠知识，从而导致钙钛矿光伏社区中的表面钝化方法合理化。