文献类型：期刊文献

英文题名：Influence of ethynyl position on benzothiadiazole based D-A-π-A dye-sensitized solar cells: spectral response and photovoltage performance

作者：Song, Xiongrong[1,2];Zhang, Weiwei[1,2];Li, Xin[3];Jiang, Huiyun[1,2];Shen, Chao[1,2];Zhu, Wei-Hong[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, Shanghai Key Lab Funct Mat Chem, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem, Collaborat Innovat Ctr Coal Based Energy I CCE, Shanghai 200237, Peoples R China;[3]KTH Royal Inst Technol, Sch Biotechnol, Div Theoret Chem & Biol, SE-10691 Stockholm, Sweden

年份：2016

卷号：4

期号：39

起止页码：9203

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY C

收录：;EI(收录号：20164202921300);WOS:【SCI-EXPANDED(收录号:WOS:000386862900010)】；

基金：This work was supported by NSFC for Creative Research Groups (21421004) and Distinguished Young Scholars (21325625), NSFC/China, Oriental Scholarship, Fundamental Research Funds for the Central Universities (WJ1416005), Scientific Committee of Shanghai (15XD1501400), and Programme of Introducing Talents of Discipline to Universities (B16017).

语种：英文

外文关键词：Open circuit voltage - Efficiency - Electrolytes - Interfaces (materials) - Titanium dioxide

摘要：The ethynyl group has been widely employed in dye-sensitized solar cells (DSSCs) as an efficient pi-spacer to prolong conjugation and promote electronic coupling at the interface of TiO2 films. However, systematic studies of the ethynyl position on metal-free organic sensitizers remain relatively rare. Herein we report indoline-based organic dyes bearing an ethynyl group at different positions of D-A-pi-A organic dyes. Based on the reference dye D1, we inserted an ethynyl unit in either the left or right side of benzothiadiazole to construct two novel dyes D2 and D3. It was found that inserting an ethynyl unit to the side of the anchoring group obtained a higher molar extinction coefficient with a red shift in the absorption band. Interestingly, D2 and D3 displayed a better photovoltaic performance with respect to D1. In particular, D3 exhibits an over 90 mV enhanced open-circuit voltage (V-oc) than D2 owing to a longer electron lifetime and slower charge recombination. With this incredible increase of V-oc, D3 bestows a high efficiency of 7.13% with respect to D1. and D2. Coadsorption strategies are exploited for further improving the cell behaviour. As a result, cosensitization with a long-wavelength-responsive dye WS-2 was demonstrated to efficiently compensate the light-harvesting, achieving an excellent efficiency of 9.83% in the iodine electrolyte. This work has paved a useful and practical way for molecular engineering in D-A-pi-A metal-free organic dyes.