Synthesis of triarylamine dyes containing secondary electron-donating groups and application in the dye-sensitized solar cells

Three triarylamine organic dyes (XS19–21) containing N,N-dimethylaniline and butoxybenzene units as secondary electron-donating groups are synthesized and characterized. When these dyes were applied into nanocrystalline TiO2 dye-sensitized solar cells through standard operations, high open-circuit voltage (more than 730 mV) were obtained. The effects of the secondary electron-donating groups as well as the π spacers on the photovoltaic performance of the DSSCs were examined. For a typical device, 5.79% of solar energy conversion efficiency (η) based on XS21 was achieved with a short-circuit photocurrent density (JSC) of 10.0 mA cm−2, an open-circuit voltage (VOC) of 782 mV, and a fill factor (ff) of 0.74.