TiO₂ films obtained by microwave-activated chemical-bath deposition used to improve TiO₂-conducting glass contact

In traditional solar cells, metal-semiconductor contacts used to extract photogenerated carriers are very important. In dye-sensitized solar cells (DSSC) not much attention has been given to contact between the TiO2 and the transparent conducting glass (TCO), which is used instead of a metal contact to extract electrons. TiO2 layers obtained by microwave-activated chemical-bath deposition (MW-CBD) are proposed to improve TiO2 contact to conducting glass. Spectra of incident photon to current conversion efficiency (IPCE) are obtained for two-photoelectrode TiO2 photoelectrochemical cells. IPCE spectra show higher values when TiO2 double layer photoelectrodes are used. In these, the first layer or contacting layer is made by MW-CBD. Best results are obtained for double layer photoelectrodes on FTO (SnO2:F) as conducting oxide substrate. Modeling of IPCE spectra reveals the importance of electrical contact and electron extraction rate at the TiO2/TCO interface. © 2009 Elsevier B.V. All rights reserved.