In this study, polymer solar cells employing poly(3-hexylthiophene) (P3HT) as a donor and fullerene derivative PC₆₁BM (phenyl-C₆₁-butyric acid methyl ester) or nonfullerene diketopyrrolopyrrole (DPP)-based small molecule (SF-DPPEH) as an acceptor are investigated. Device based on SF-DPPEH shows a remarkably high V_OC of 1.20 V, whereas analogous device based on PC₆₁BM only delivers a V_OC of 0.64 V. Employing transient photovoltage/photocurrent techniques, we measure charge carrier lifetime and density and nongeminate recombination rate in the photoactive layer and correlate material energetics and charge recombination dynamics with the change of V_OC in the devices; thus, the extent to which two factors limit V_OC can be quantified.

中文翻译：

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了解基于二酮吡咯并吡咯小分子受体的聚合物太阳能电池的增强的开路电压

在这项研究中，采用聚（3-己基噻吩）（P3HT）作为施主和富勒烯衍生物PC ₆₁ BM（苯基-C ₆₁丁酸甲酯）或基于非富勒烯二酮吡咯并吡咯（DPP）的小分子（SF-研究了作为受体的DPPEH）。基于SF-DPPEH的器件显示出1.20 V的极高V _OC，而基于PC ₆₁ BM的类似器件仅提供0.64 V的V _OC。采用瞬态光电压/光电流技术，我们测量了电荷载流子的寿命和密度，并且进行了非对接重组在光敏层中的速率以及与V _OC的变化相关的材料能量和电荷复合动力学在设备中；因此，向其中两个因素限制的程度V _OC可以被量化。