A Triphenylamine Dye Model for the Study of Intramolecular Energy Transfer and Charge Transfer in Dye-Sensitized Solar Cells

A novel dye (2TPA-R), containing two triphenylamine (TPA) units connected by a vinyl group and rhodanine-3-acetic acid as the electron acceptor, is designed and synthesized successfully to reveal the working principles of organic dye in dye-sensitized solar cells (DSSCs). 2TPA and TPA-R, which consist of two TPA units connected by vinyl and a TPA unit linked with rhodanine-3-acetic acid, respectively, are also synthesized as references to study the intramolecular energy transfer (EnT) and charge transfer (ICT) processes of 2TPA-R in CH2Cl2 solution and on a TiO2 surface. The results suggest that the intramolecular EnT and ICT processes show a positive effect on the performance of DSSCs. However, the flexible structure and less-adsorbed amount of dye on TiO2 may make it difficult to improve the efficiency of DSSCs. This study on intramolecular EnT and ICT processes acts as a guide for the design and synthesis of efficient organic dyes in the future.