Space charge effects can significantly degrade charge collection in organic photovoltaics (OPVs), especially in thick‐film devices. The two main causes of space charge are doping and imbalanced transport. Although these are completely different phenomena, they lead to the same voltage dependence of the photocurrent, making them difficult to distinguish. Herein, a method is introduced on how the build‐up of space charge due to imbalanced transport can be monitored in a real operating organic solar cell. The method is based on the reconstruction of quantum efficiency spectra and requires only optical input parameters that are straightforward to measure. This makes it suitable for the screening of new OPV materials. Furthermore, numerical and analytical means are derived to predict the impact of imbalanced transport on charge collection. It is shown that when charge recombination is sufficiently reduced, balanced transport is not a necessary condition for efficient thick‐film OPVs.

中文翻译：

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观看有机太阳能电池中积累的空间电荷

空间电荷效应会大大降低有机光伏（OPV）中的电荷收集，特别是在厚膜器件中。造成空间电荷的两个主要原因是掺杂和传输不平衡。尽管这些是完全不同的现象，但是它们导致光电流的电压依存性相同，因此很难区分。本文介绍了一种方法，该方法可用于在实际运行的有机太阳能电池中如何监测由于运输不平衡而导致的空间电荷积聚。该方法基于量子效率谱的重建，仅需要直接测量的光学输入参数。这使其适合筛选新的OPV材料。此外，推导了数值和分析手段来预测不平衡传输对电荷收集的影响。