Triphenylamine dyes bearing 5-phenyl-2-(arylthiophen-2-yl)thiazole bridge for dye sensitized solar cells

Three triphenylamine dyes were synthesized with 5-phenyl-2-(arylthiophen-2-yl)thiazole as pi bridge and cyanoacrylic acid as the acceptor. Three dyes differ in the aryl ring binding with the acceptor in the pi bridge, which leads to different photophysical properties, molecular planarity, energy level and accordingly the photoelectric conversion efficiency. The insertion of furan and thiophene units in pi bridge attain broader absorption spectra and better molecular coplanarity, contributing to the distinct improvement of J(SC) and hence the photovoltaic performance. On the other hand, the presence of benzene unit raises the LUMO level and increases the drive force for the electron injection into TiO2, which enhance V-OC. Among three dyes, dye bearing two thiophene units sensitized DSSC achieves a cell efficiency 6.90% due to better J(SC) (14.09 mA cm(2)) and V-OC (0.73 V).

Automated summary

By adjusting the molecular structure, the photophysical properties, molecular planarity, and energy levels can be altered, thus affecting the photoelectric conversion efficiency. Inserting furan and thiophene units in the pi bridge is beneficial for enhancing J(SC) and photovoltaic performance, while the benzene unit helps to enhance V-OC.