| Abstract: |
Time-resolved infrared measurements indicate ultrafast, < 350 fs electron injection from (4,4'dcb)2Ru(NCS)2 (1) and (5,5'dcb)2Ru(NCS)2 (2) to nanostructured TiO2 electrodes. {(4,4'dcb) = (4,4'-COOH-2,2'-bipyridine)} Although rapid, the injection from 2 apparently occurs with a lower quantum yield, then that from 1. explaining a lower overall photon-to-current efficiency for 2/TiO2 solar cells. Transient visible spectroscopy reveals similar rates of both halide oxidation and injected electron-oxidized dye recombination for the two sensitizers. Substituting SnO2 for TiO2 increases the electron injection yield from 2 in the case of transparent metal oxide films and improves the photon to current efficiency. Results indicate a wavelength-dependent electron injection yield. |
