The rapidly growing interest in indoor photovoltaics for low light energy harvesting applications further necessitates an understanding of factors that impact the performance and efficiency of these devices under low light. The external radiative efficiency of a photovoltaic device is an important parameter to help understand the impact of nonradiative recombination on the open circuit voltage (V_oc) of the device. In this work, we compare the behavior of V_oc with the photocurrent under low light for two perovskite PV devices, one of which is fabricated with an additional surface passivation treatment. In order to explain the observed V_oc differences between the two cells, we performed absolute electroluminescence measurements on both cells and explored the current density dependence of the external radiative efficiency between the two cells. This dependence is quantified with a mathematical treatment that takes advantage of a widely accepted recombination current model. Our findings indicate that surface-passivated cells substantially benefit from a modest decrease in the reverse saturation current density associated with nonradiative losses, resulting in large V_oc enhancements and increased luminescence extraction efficiency, particularly under low light conditions.

中文翻译：

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室内低光照条件下钙钛矿太阳能电池开路电压的见解

人们对用于弱光能量收集应用的室内光伏发电的兴趣迅速增长，进一步需要了解影响这些设备在弱光下性能和效率的因素。光伏器件的外部辐射效率是一个重要参数，有助于了解非辐射复合对器件开路电压 ( V _oc ) 的影响。在这项工作中，我们比较了两种钙钛矿光伏器件在弱光下的V _oc行为和光电流，其中一种是通过额外的表面钝化处理制造的。为了解释观察到的两个电池之间的V _oc差异，我们对两个电池进行了绝对电致发光测量，并探索了两个电池之间的外部辐射效率的电流密度依赖性。这种依赖性通过利用广泛接受的重组电流模型的数学处理来量化。我们的研究结果表明，表面钝化电池大大受益于与非辐射损耗相关的反向饱和电流密度的适度降低，从而导致V _oc大幅增强并提高发光提取效率，特别是在低光条件下。