|Snaith, H.J.; Karthikeyan, C.S.; Petrozza, A.; Teuscher, J.; Moser, J.-E.; Nazeeruddin, M.K.; Thelakkat, M.; Grätzel, M.: High extinction coefficient antenna dye in solid-state dye-sensitised solar cells: a photo-physical and electronic study, Journal of Physical Chemistry C, 112, 75627566 (2008) -- DOI: 10.1021/jp801714u|
We present a photophysical and device-based investigation of a new bipyridyl−NCS ruthenium complex sensitizer with an extended π system, in both sensitized TiO2 and incorporated into solid-state dye-sensitized solar cells. We compare this new sensitizer to an analog dye without the extended π system. We observe very similar excited-state absorption spectra and charge recombination kinetics for the two systems. However, the π-extended senstizer has a phenomenally enhanced molar extinction coefficient which translates into far greater light harvesting and current collection in solid-state dye-sensitized solar cells. We also infer from transient photovoltage measurements that positioning the pendent extended π system away from the TiO2 surface has induced a favorable dipole shift, generating enhanced open-circuit voltage. The resulting power conversion efficiency for the solar cell has been increased from 2.4% to 3.2% when comparing the new sensitizer to an analogy with no pendent group.
- Project: Solarzellen / Solar Cells: Organic Solarcells