Dye-sensitized solar cells based on functionalized truxene structure

Three new metal-free organic dyes (TX1, TX2 and TX3) based on truxene core structure, with triphenylamine as the electron donor, thiophene as the pi spacers, and cyanoacetic acid or rhodanine-3-acetic acid as the electron acceptor are designed and synthesized. Their UV-vis absorption spectra, electrochemical and photovoltaic properties were investigated. The cyanoacrylic acid is verified to be a better acceptor unit (meanwhile the anchoring group) compared to the rhodanine-3-acetic acid. And also, two anchoring groups in TX2 could provide stronger adsorption ability on the TiO2 surface. In addition, the EIS results indicate a slower charge recombination processes for TX2. As a result, dye TX2 bearing two cyanoacetic acid outperforms the other two dyes, exhibiting the photo-conversion efficiency of 2.64%, with J(SC) = 5.09 mA cm(-2), V-OC = 729 mV, FF = 71.1. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.