Organic photovoltaic (OPV) cells have attracted significant interest for indoor applications with the arrival of the Internet of Things. However, the studies on the essential fundamental issues are still insufficiency under low light. Thus, the properties of OPV cells for low light applications need further clarification. Here, we systematically studied the effect of series resistance (R_s) on the PBDB-TF:IT-M-based device by introducing external R_s and tuning active layer thickness. Regardless of enlarging external R_s or increasing active layer thickness, the efficiencies were observably improved under low light, compared with the AM 1.5G condition. The phenomenon can be mainly attributed to impressive fill factor (FF) under low light due to the restrained recombination processes. Furthermore, we provided the energy distribution through the optical analysis for the OPV cells. The fabricated OPV cells (4 cm²) via the blade-coating method output an outstanding power conversion efficiency (PCE) of 21.2% and 10.5% with optimal thicknesses of 181 ± 37 nm under weak LED light and 0.5% sun, respectively, which are significantly higher than the value of 5.02% under the AM 1.5G condition. Our work shows that OPV cells have great potential in industrialization for low light applications.

随着物联网的到来，有机光伏（OPV）电池引起了室内应用的极大兴趣。但是，对于基本的基本问题的研究仍然不足。因此，需要进一步阐明用于弱光应用的OPV电池的特性。在这里，我们通过引入外部R _s和调整有源层厚度，系统研究了串联电阻（R _s）对基于PBDB-TF：IT-M的器件的影响。不管扩大外部R _s或增加有源层厚度，与AM 1.5G条件相比，在弱光下效率明显提高。该现象主要归因于重组过程受限制的弱光下令人印象深刻的填充因子（FF）。此外，我们通过光学分析提供了OPV电池的能量分布。通过刮涂法制造的OPV电池（4 cm ²）在弱LED光线和0.5％阳光下分别具有21.2％和10.5％的出色功率转换效率（PCE），最佳厚度分别为181±37 nm，这是最佳的。明显高于AM 1.5G条件下的5.02％。我们的工作表明，OPV电池在弱光应用的工业化方面具有巨大潜力。