A pair of new donor-π-acceptor dyes that absorb toward the red region of the visible spectrum (CAD 1 and CAD 2) utilizing indolium cationic acceptor units have been synthesized for use in p-type dye-sensitized solar cells (p-DSC). Their optical and electrochemical properties were determined experimentally, including application of ultrafast transient absorption and time-resolved infrared spectroscopies. Our results are supported by computational modeling. NiO-based p-DSCs with CAD 1 and CAD 2 gave short-circuit photocurrent densities of 3.6 and 3.3 mA cm-2, respectively, which are substantially higher than that of any previous red-absorbing p-DSC. These results are a step toward tandem dye-sensitized solar cells that absorb higher-energy photons at the TiO2 anode and lower-energy photons at the NiO cathode. Routes to further improve the efficiency of NiO DSCS are also discussed.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy (all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films