Inter-relation between size and arrangement of TiO2 nanoparticle layers on efficiency of dye-sensitized solar cells

The effects of TiO2 layer arrangement as photo-anode on the efficiency of dye-sensitized solar cells were investigated and presented. Four TiO2 nanoparticles being different from the TiO2 particle sizes and phases were prepared and characterized with TEM, AFM and XRD analyses. These TiO2 particles were used to prepare three-layered photo-anode with different layer arrangements. The J-V measurements and impedance spectroscopy of the assembled solar cells with these photo-anodes and N3 dye were investigated and interpreted. The photo-anode in which the particles were arranged from large to small (CBA) and the photo-anode in which the particle size is equal (BBB) presented the best efficiency. The BBB performance was related to the appropriate particle size in the B layer and was a driving force for electron transfer, which is inducted by the oxidized dyes. In the CBA sample, this driving force was enhanced by the different particle sizes in the layer interfaces. [GRAPHICS] .