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 (E_nT) and charge transfer (ICT) processes of 2TPA-R in CH₂Cl₂ solution and on a TiO₂ surface. The results suggest that the intramolecular E _nT 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 E_nT and ICT processes acts as a guide for the design and synthesis of efficient organic dyes in the future.