Abstract
Charge transfer from photoexcited dye molecules to a semiconductor substrate forms the basis of dye sensitized solar cells (DSCs); the overall effectiveness of a DSC device is critically dependent upon the efficiency of this process due to competition with other de-excitation channels. In this paper, we experimentally derive timescales for the charge transfer process in model water splitting DSCs. We studied two organometallic dye complexes adsorbed onto a rutile TiO2(110) substrate, the dye molecules were deposited in ultra-high vacuum using electrospray deposition. DFT simulations were used to calculate the spatial distribution of orbitals relevant to the charge transfer process. The core-hole clock implementation of resonant photoemission spectroscopy was used to determine upper limits on charge transfer timescales for previously unoccupied orbitals, which were found to be in the low-femtosecond regime apart from one orbital found to have an upper limit in the sub-femtosecond regime.
Original language | English |
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Article number | 224706 |
Journal | Journal of Chemical Physics |
Volume | 137 |
Issue number | 22 |
DOIs | |
Publication status | Published - 4 Dec 2012 |