文献类型：期刊文献

英文题名：Influence of the Donor Size in D-π-A Organic Dyes for Dye-Sensitized Solar Cells

作者：Yang, Jiabao[1,2,3];Ganesan, Paramaguru[3];Teuscher, Joel[3];Moehl, Thomas[3];Kim, Yong Joo[3,4];Yi, Chenyi[3];Comte, Pascal[3];Pei, Kai[1,2];Holcombe, Thomas W.[3];Nazeeruddin, Mohammad Khaja[3];Hua, Jianli[1,2];Zakeeruddin, Shaik M.[3];Tian, He[1,2];Graetzel, Michael[3]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China;[3]Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland;[4]Dongjin Semichem Co Ltd, R&D Ctr DSC Team, Hwasung 445935, South Korea

年份：2014

卷号：136

期号：15

起止页码：5722

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20141817647285);WOS:【SCI-EXPANDED(收录号:WOS:000334657600037)】；

基金：This work was supported by NSFC/China (2116110444, 21172073, 91233207 and 21372082), the National Basic Research 973 Program (2013CB733700), and the Fundamental Research Funds for the Central Universities (WJ0913001). PG is gratefully acknowledges financial support from the Swiss confederation under Swiss Government Scholarship programme and UGC, India. MG thanks the Swiss National Science Foundation and European Research Council (ERC) for an Advanced Research Grant (No. 247404) funded under the CE-Mesolight project. Yang would like to thank the funding of the visiting program, which is supported by China Scholarship Council (CSC) and Dr. Kuan-Lin Wu (National Tsing Hua University, Taiwan) for fruitful discussion.

语种：英文

外文关键词：Charge transfer - Electrochemical impedance spectroscopy - Cobalt compounds - Dye-sensitized solar cells - Electrochemical electrodes - Titanium dioxide - Transient absorption spectroscopy - Photolysis

摘要：We report two new molecularly engineered push-pull dyes, i.e., YA421 and YA422, based on substituted quinoxaline as a pi-conjugating linker and bulky-indoline moiety as donor and compared with reported IQ4 dye. Benefitting from increased steric hindrance with the introduction of bis(2,4-dihexyloxy)benzene substitution on the quinoxaline, the electron recombination between redox electrolyte and the TiO2 surface is reduced, especially in redox electrolyte employing Co(II/III) complexes as redox shuttles. It was found that the open circuit photovoltages of IQ4, YA421, and YA422 devices with cobalt-based electrolyte are higher than those with iodide/triiodide electrolyte by 34, 62, and 135 mV, respectively. Moreover, the cells employing graphene nanoplatelets on top of gold spattered film as a counter electrode (CE) show lower charge-transfer resistance compared to platinum as a CE. Consequently, YA422 devices deliver the best power conversion efficiency due to higher fill factor, reaching 10.65% at AM 1.5 simulated sunlight. Electrochemical impedance spectroscopy and transient absorption spectroscopy analysis were performed to understand the electrolyte influence on the device performances with different counter electrode materials and donor structures of donor-pi-acceptor dyes. Laser flash photolysis experiments indicate that even though the dye regeneration of YA422 is slower than that of the other two dyes, the slower back electron transfer of YA422 contributes to the higher device performance.