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 π 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 Jsc = 5.09 mA cm–2, Voc = 729 mV, FF = 71.1.

Graphical abstractThree new truxene based organic dyes (named TX1, TX2 and TX3) are synthesized and their photovoltaic properties were investigated. Dye TX2 bearing two cyanoacetic acid parts exhibited the highest photo-conversion efficiency of 2.64%.Figure optionsDownload full-size imageDownload as PowerPoint slide