Wu Jianglin, Si Changfeng, Chen Yao, Yang Lin, Hu Bin, Chen Guo, Lu Zhiyun, Huang Yan
Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P.R. China.
Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai, 200072, P.R. China.
Chemistry. 2018 Mar 2;24(13):3234-3240. doi: 10.1002/chem.201705140. Epub 2018 Feb 1.
A series of unsymmetrical arene-1,3-squaraine (USQ) derivatives with two, three, or four hydroxy (-OH) substituents, namely, USQ-2-OH, USQ-3-OH, or USQ-4-OH, respectively, were designed and synthesized, and the effect of the number of hydroxy groups on the optoelectronic properties of USQs were investigated. Despite the three compounds having similar UV/Vis absorption and HOMO energy levels, solution-processed bulk-heterojunction (BHJ) small-molecule organic solar cells with USQ-3-OH as electron-donor materials exhibit the highest power conversion efficiency of 6.07 %, which could be mainly attributed to the higher hole mobility and smaller phase separation. It is also noteworthy that the short-circuit current (J ) of the USQ-3-OH-based device is as high as 14.95 mA cm , which is the highest J values reported for squaraine-based BHJ solar cells to date. The results also indicate that more -OH substituents on squaraine dyes do not necessarily lead to better photovoltaic performance.
设计并合成了一系列具有两个、三个或四个羟基（-OH）取代基的不对称芳基-1,3-方酸菁（USQ）衍生物，分别为USQ-2-OH、USQ-3-OH或USQ-4-OH，并研究了羟基数对USQ光电性能的影响。尽管这三种化合物具有相似的紫外/可见吸收和最高占据分子轨道（HOMO）能级，但以USQ-3-OH作为电子给体材料的溶液处理体相异质结（BHJ）小分子有机太阳能电池表现出最高6.07%的功率转换效率，这主要归因于较高的空穴迁移率和较小的相分离。同样值得注意的是，基于USQ-3-OH的器件的短路电流（J）高达14.95 mA cm，这是迄今为止基于方酸菁的BHJ太阳能电池报道的最高J值。结果还表明，方酸菁染料上更多的-OH取代基不一定会带来更好的光伏性能。
