The effect of cyclic thiourea functionalization and β,β′-dialkylbithiophene linker on the performance of triphenylamine dyes
作者:Yinju Guo、Jianli Su、Zhongwei An、Xinbing Chen、Pei Chen
DOI:10.1016/j.molstruc.2015.04.012
日期:2015.8
Four new dyes (T-C1, T-C6, S-C1 and S-C6) with beta,beta '-dialkylbithiophene as pi-linkers were synthesized and utilized in dye-sensitized solar cells (DSSCs). Compared with the reference dyes (T-C0 and AZ6) with bithiophene as pi-linkers, these dyes show blue-shifted absorption bands, and their DSSCs produce lower short-circuit current and high open-circuit voltage. These may be caused by the increase of dihedral angle between two thiophenes. On the one hand, the molecular conjugations are decreased: on the other hand, steric effect of the whole structures are increased. Compared with the triphenylamine dyes (T-C0, T-C1 and T-C6), the cyclic thiourea functionalized dyes (AZ6, S-C1 and S-C6) exhibit better photophysical and photovoltaic performances. However, the superiority of cyclic thiourea functionalization is gradually disappearing with the increased steric effect of the pi-linkers. (C) 2015 Elsevier B.V. All rights reserved.