Guo Xia, Zhang Maojie, Cui Chaohua, Hou Jianhui, Li Yongfang
Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Jun 11;6(11):8190-8. doi: 10.1021/am500836u. Epub 2014 May 20.
The photovoltaic performance of poly(3-hexylthiophene) (P3HT) has been improved greatly by using indene-C60 bisadduct (ICBA) as acceptor instead of phenyl-C61-butyric acid methyl ester (PCBM). However, the solvent of dichlorobenzene (DCB) used in fabricating polymer solar cells (PSCs) limited the application of the PSCs, because of the environmental problem caused by the harmful halogenated solvent. In this work, we fabricated the PSCs based on P3HT/ICBA processed with four low-harmful non-halogenated solvents of toluene, o-xylene, m-xylene, and p-xylene. The PSCs based on P3HT/ICBA (1:1, w/w) with toluene as the solvent exhibit the optimized power conversion efficiency (PCE) of 4.5% with open-circuit voltage (Voc) of 0.84 V, short circuit current density (Jsc) of 7.2 mA/cm(2), and fill factor (FF) of 71%, under the illumination of AM 1.5G at 100 mW/cm(2). Upon using 1% N-methyl pyrrolidone (NMP) as a solvent additive in the toluene solvent, the PCE of the PSCs was greatly improved to 6.6% with a higher Jsc of 10.3 mA/cm(2) and a high FF of 75%, which is even higher than that of the devices fabricated with halogenated DCB solvent. The X-ray diffraction (XRD) measurement shows that the crystallinity of P3HT increased with the NMP additive. The investigations on morphology of the active layers by atomic force microscopy (AFM) and transmission electron microscopy (TEM) indicate that the NMP additive promotes effective phase separation and formation of nanoscaled interpenetrating network structure of the active layer, which is beneficial to the improvement of Jsc and PCE for the PSCs fabricated with toluene as the solvent.
通过使用茚-C60双加合物（ICBA）作为受体而非苯基-C61-丁酸甲酯（PCBM），聚（3-己基噻吩）（P3HT）的光伏性能得到了极大提升。然而，用于制备聚合物太阳能电池（PSC）的二氯苯（DCB）溶剂限制了PSC的应用，因为这种有害的卤化溶剂会引发环境问题。在这项工作中，我们基于P3HT/ICBA，使用甲苯、邻二甲苯、间二甲苯和对二甲苯这四种低危害非卤化溶剂制备了PSC。以甲苯为溶剂的基于P3HT/ICBA（1:1，w/w）的PSC在100 mW/cm²的AM 1.5G光照下，展现出4.5%的优化功率转换效率（PCE），开路电压（Voc）为0.84 V，短路电流密度（Jsc）为7.2 mA/cm²，填充因子（FF）为71%。在甲苯溶剂中使用1%的N-甲基吡咯烷酮（NMP）作为溶剂添加剂后，PSC的PCE大幅提升至6.6%，Jsc更高，达到10.3 mA/cm²，FF为75%，甚至高于用卤化DCB溶剂制备的器件。X射线衍射（XRD）测量表明，添加NMP后P3HT的结晶度增加。通过原子力显微镜（AFM）和透射电子显微镜（TEM）对活性层形态的研究表明，NMP添加剂促进了活性层的有效相分离和纳米级互穿网络结构的形成，这有利于提高以甲苯为溶剂制备的PSC的Jsc和PCE。
