State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology , Guangzhou 510630, P. R. China.
ACS Appl Mater Interfaces. 2017 Sep 6;9(35):29907-29916. doi: 10.1021/acsami.7b07704. Epub 2017 Aug 24.
Ternary bulk heterojunction (BHJ) is a brilliant photovoltaic technology for improving the performance of organic solar cells (OSCs), because the light absorption range can be significantly extended by using multiple donors or acceptor materials. In this paper, coumarin7 (C7), a small organic molecule typical led used in organic light-emitting diodes, was initially exploited as second electron-donor component in ternary bulk heterojunction OSCs along with conventional blend system spolythieno[3,4-b]-thiophene/benzodithiophene(PTB7) and [6,6]-phenyl-C71 -butyric acid methyl(PC BM). A champion PCE value of 10.28% was realized in the ternary OSCs when incorporated with 10 wt % C7 doping ratio in the donors, corresponding to about 35% enhancement compared with the PTB7:PCBM-based OSCs, a high fill factor (FF) of 75.03%, a short-circuit currentdensity (J) of 18.72 mA cm and an open-circuit voltage (V) of 0.73 V. The enhanced performance of the ternary OSCs can be attributed to the simultaneous improvement of the FF and the J. In addition to extended light absorption, a perfect nanofiber filament active layer morphology is obtained due to the good compatibility between C7 and PTB7, which facilitates the balance of charge transportation and the suppression of charge recombination. This investigation suggests that coumarin derivatives, which have completely different structure with polymer donors, can also be used to fabricate ternary solar cells and have the potential applications to obtain amazing performance after further device engineering and optimization.
三元体异质结（BHJ）是一种卓越的光伏技术，可用于提高有机太阳能电池（OSC）的性能，因为使用多种供体或受体材料可以显著扩展光吸收范围。在本文中，香豆素 7（C7）最初被用作三元体异质结 OSC 中的第二电子供体组件，与传统的混合体系 spolythieno[3,4-b]-thiophene/benzodithiophene（PTB7）和[6,6]-phenyl-C71 -butyric acid methyl（PC BM）一起使用。当在供体中掺入 10wt%的 C7 掺杂比时，三元 OSC 的实现了 10.28%的冠军 PCE 值，与基于 PTB7：PCBM 的 OSC 相比，提高了约 35%，高填充因子（FF）为 75.03%，短路电流密度（J）为 18.72 mA cm 和开路电压（V）为 0.73 V。三元 OSC 的性能增强归因于 FF 和 J 的同时提高。除了扩展光吸收之外，由于 C7 和 PTB7 之间的良好相容性，还获得了完美的纳米纤维细丝活性层形态，这有利于电荷输运的平衡和抑制电荷复合。这项研究表明，香豆素衍生物与聚合物供体具有完全不同的结构，也可以用于制造三元太阳能电池，并有可能在进一步的器件工程和优化后获得惊人的性能。
