文献类型：期刊文献

英文题名：Incorporating Benzotriazole Moiety to Construct D-A-π-A Organic Sensitizers for Solar Cells: Significant Enhancement of Open-Circuit Photovoltage with Long Alkyl Group

作者：Cui, Yan[1,2];Wu, Yongzhen[3,4];Lu, Xuefeng[1,2];Zhang, Xi[1,2];Zhou, Gang[1,2];Miapeh, Fohn B.[3,4];Zhu, Weihong[3,4];Wang, Zhong-Sheng[1,2]

机构：[1]Fudan Univ, Dept Macromol Sci, Dept Chem, Shanghai 200438, Peoples R China;[2]Fudan Univ, Adv Mat Lab, Shanghai 200438, Peoples R China;[3]E China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[4]E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China

年份：2011

卷号：23

期号：19

起止页码：4394

外文期刊名：CHEMISTRY OF MATERIALS

收录：;EI(收录号：20114114412862);WOS:【SCI-EXPANDED(收录号:WOS:000295487800015)】；

基金：This work was financially supported by the National Basic Research Program (2011CB933302) of China, the National Natural Science Foundation of China (20971025, 90922004, and 50903020), the Shanghai nongovernmental international cooperation program (10530705300), Shanghai Leading Academic Discipline Project (B108), the Oriental Scholarship, the Fundamental Research Funds for the Central Universities (WK1013002), and Jiangsu Major Program (BY2010147).

语种：英文

外文关键词：dye sensitizers; solar cells; benzotriazole; open-circuit photovoltage; charge recombination

摘要：Two novel benzotriazole-containing organic dyes based on D-A-pi-A configuration, WS-5 with octyl group and WS-8 with methyl group, have been designed and synthesized for use in dye-sensitized solar cells (DSSCs). Compared with the traditional D-pi-A sensitizers, the benzotriazole unit as an additional acceptor has several merits: (i) essentially facilitating the electron transfer from the donor to the acceptor/anchor; (ii) conveniently tailoring the solar cell performance with a facile structural modification on 2-position in the benzotriazole unit; and (iii) the nitrogen-containing heterocyclic group of benzotriazole being expected to improve the open-circuit photovoltage. The analysis of controlled intensity modulated photovoltage spectroscopy reveals that the replacement of methyl with octyl group enhances electron lifetime by 4-fold and retards charge recombination rate constant by 4-fold. The two dye-loaded TiO(2) films possess almost the same conduction band position under the same condition, as revealed by the charge densities at open-circuit against open-circuit photovoltage. Therefore, the significant enhancement of open-circuit photovoltage from methyl to octyl group is attributed to the suppressed charge recombination. Under simulated AM1.5G solar light (100 mW cm(-2)), the DSSC based on WS-5 produces a short-circuit photocurrent of 13.18 mA cm(-2), an open-circuit photovoltage of 0.78 V, a fill factor of 0.78, corresponding to a power conversion efficiency of 8.02%.