Influence of various electron-donating triarylamine groups in BODIPY sensitizers on the performance of dye-sensitized solar cells

• Four boron dipyrromethene (BODIPY) type sensitizers were synthesized.
• The BODIPY sensitizers contain triarylamine donors with different rigidities.
• These BODIY dyes were applied in dye-sensitized solar cells (DSSCs).
• The fluorescence quantum yield and lifetime influenced the cell performance.
• The fluorescence quantum yield and lifetime related to molecules' rigidities.

Four donor-π bridge-acceptor structured boron dipyrromethene type sensitizers bearing triarylamine donors with different rigidities were synthesized and applied in dye-sensitized solar cells. The influence of different triarylamine donors on the optical, electrochemical properties and photovoltaic performances of sensitizers was systematically investigated. It was shown that the photovoltaic performance of boron dipyrromethene type sensitizer-based cell increased with increasing the fluorescence quantum yield and fluorescence lifetime of the corresponding sensitizers, which are believed to be closely related to the rigidities of the donor groups in the molecule. The best performance was realized for the cell based on rigid 9-phenyl-carbazole-substituted boron dipyrromethene sensitizer (ZH-b) with a fluorescence quantum yield of 0.516 and a fluorescence lifetime of 4.02 ns, resulting in a short circuit photocurrent density of 14.10 mA/cm2 and an overall conversion efficiency of 4.42%, which are fairly good results achieved for boron dipyrromethene type sensitizer-based solar cell.