Co-sensitization of microporous TiO2 electrodes with dye molecules and quantum-sized semiconductor particles

The microporous titanium dioxide (TiO2) film has been prepared on a conduct ing glass substrate. A seven-fold enhancement in energy conversion efficien cy of the dye-sensitized solar cell was achieved by pre-depositing a closel y packed TiO2 thin film on the surface of the conducting glass. Moreover, F eS2 particles were coated on TiO2 electrode by chemical reaction of iron pe ntacarbonyl with sulfur in xylene. Both atomic force microscope (AFM) and p hotoelectric studies suggest that the FeS2 quantum-sized particles play a d ominate role in the photoelectric conversion of FeS2/TiO2 electrode, while the FeS2 large particles have less or even no contribution to the photo-cur rent. Furthermore, the TiO2 electrode has been co-modified with phthalocyan ine dye molecules and quantum-sized semiconductor particles. Go-sensitizati on of the TiO2 electrode with CdSe particles and ZnTCPc dye molecules not o nly extends the photoresponse of CdSe/TiO2 electrode further into red regio n, but also improve the quantum efficiency of photoelectric conversion. We believe that such a co-sensitization technique should be of general importa nce in designing novel solar energy conversion devices. (C) 2000 Elsevier S cience B.V. All rights reserved.