Zhang Kai, Zhong Chengmei, Liu Shengjian, Mu Cheng, Li Zhengke, Yan He, Huang Fei, Cao Yong
Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology , Guangzhou, Guangdong 510641, P. R. China.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10429-35. doi: 10.1021/am501920z. Epub 2014 Jun 24.
A cross-linkable water/alcohol soluble conjugated polymer (WSCP) material poly[9,9-bis(6'-(N,N-diethylamino)propyl)-fluorene-alt-9,9-bis(3-ethyl(oxetane-3-ethyloxy)-hexyl) fluorene] (PFN-OX) was designed. The cross-linkable nature of PFN-OX is good for fabricating inverted polymer solar cells (PSCs) with well-defined interface and investigating the detailed working mechanism of high-efficiency inverted PSCs based on poly[4,8-bis(2-ethylhexyloxyl)benzo[1,2-b:4,5-b']dithio-phene-2,6-diyl-alt-ethylhexyl-3-fluorothithieno[3,4-b]thiophene-2-carboxylate-4,6-diyl] (PTB7) and (6,6)-phenyl-C71-butyric acid methyl ester (PC71BM) blend active layer. The detailed working mechanism of WSCP materials in high-efficiency PSCs were studied and can be summarized into the following three effects: a) PFN-OX tunes cathode work function to enhance open-circuit voltage (Voc); b) PFN-OX dopes PC71BM at interface to facilitate electron extraction; and c) PFN-OX extracts electrons and blocks holes to enhance fill factor (FF). On the basis of this understanding, the hole-blocking function of the PFN-OX interlayer was further improved with addition of a ZnO layer between ITO and PFN-OX, which led to inverted PSCs with a power conversion efficiency of 9.28% and fill factor high up to 74.4%.
设计了一种可交联的水/醇溶性共轭聚合物（WSCP）材料聚[9,9-双（6'-（N,N-二乙氨基）丙基）-芴-alt-9,9-双（3-乙基（氧杂环丁烷-3-乙氧基）己基）芴]（PFN-OX）。PFN-OX的可交联特性有利于制备具有明确界面的倒置聚合物太阳能电池（PSC），并研究基于聚[4,8-双（2-乙基己氧基）苯并[1,2-b:4,5-b']二噻吩-2,6-二基-alt-乙基己基-3-氟噻吩并[3,4-b]噻吩-2-羧酸酯-4,6-二基]（PTB7）和（6,6）-苯基-C71-丁酸甲酯（PC71BM）共混活性层的高效倒置PSC的详细工作机制。研究了WSCP材料在高效PSC中的详细工作机制，可总结为以下三种效应：a）PFN-OX调节阴极功函数以提高开路电压（Voc）；b）PFN-OX在界面处掺杂PC71BM以促进电子提取；c）PFN-OX提取电子并阻挡空穴以提高填充因子（FF）。基于这种理解，通过在ITO和PFN-OX之间添加ZnO层进一步改善了PFN-OX中间层的空穴阻挡功能，这导致倒置PSC的功率转换效率达到9.28%，填充因子高达74.4%。
