文献类型：期刊文献

英文题名：Porphyrins bearing long alkoxyl chains and carbazole for dye-sensitized solar cells: tuning cell performance through an ethynylene bridge

作者：Wang, Yueqiang[1,2];Li, Xin[3];Liu, Bo[1,2];Wu, Wenjun[1,2];Zhu, Weihong[1,2];Xie, Yongshu[1,2]

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]Royal Inst Technol, Dept Theoret Chem & Biol, Sch Biotechnol KTH, Stockholm, Sweden

年份：2013

卷号：3

期号：34

起止页码：14780

外文期刊名：RSC ADVANCES

收录：;EI(收录号：20133416634464);WOS:【SCI-EXPANDED(收录号:WOS:000322737400075)】；

基金：This work was financially supported by NSFC (21072060), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, Program for New Century Excellent Talents in University (NCET-11-0638), Innovation Program of Shanghai Municipal Education Commission, the Fundamental Research Funds for the Central Universities (WK1013002), and SRFDP (20100074110015).

语种：英文

外文关键词：Design for testability - Fluorescence spectroscopy - Chains - Cyclic voltammetry - Efficiency - Heterojunctions - Solar power generation - Dye-sensitized solar cells - Solubility - Molecules - Titanium dioxide - Polycyclic aromatic hydrocarbons

摘要：Two novel porphyrin dyes (Q1 and Q2) bearing alkoxyl chains with a carbazole moiety as the electron donor have been synthesized and utilized as sensitizers for dye-sensitized solar cells (DSSCs). Compared with Q2, the molecule of Q1 has an additional ethynylene bridge between the carbazole moiety and the porphyrin framework. Photophysical and electrochemical properties of the two dyes were investigated by UV-vis, fluorescence spectroscopy and cyclic voltammetry. DFT calculations indicated that Q2 has a more twisted non-planar conformation associated with a smaller p conjugation size because of the absence of ethynylene bridge, which resulted in its better solubility and larger amount of adsorption on TiO2. Compared with Q1, Q2 showed better photovoltaic performance, with a short-circuit photocurrent density (J(sc)) of 11.3 mA cm(-2), an open-circuit photovoltage (V-oc) of 0.68 V, and a fill factor (ff) of 0.71, corresponding to an overall conversion efficiency of 5.51% under standard global AM 1.5 solar light conditions. The additional ethynylene bridge in Q1 extends the absorption bands to a longer wavelength region with the absorption threshold of 743 nm on the TiO2 film compared with that of 681 nm for Q2, but the cell efficiency is decreased to 2.22%, which may be ascribed to the worse solubility and stronger aggregation tendency resulting from the better molecule planarity. These results indicate that the extension of the absorption bands to a longer wavelength region by the introduction of an additional ethynylene bridge may result in worse solubility and more severe aggregation, and thus decrease the cell efficiency. For the design of efficient DSSC sensitizers, these contradictory effects must be fully considered and well balanced.