Efficient dye-sensitized solar cells with surface-modified photoelectrodes

Abstract

The influence of a mixed overlayer comprising titanium dioxide (TiO2) and niobium pentoxide (Nb2O5), which was coated on the surfaces of TiO2 nanoporous photoelectrodes, on the performance of dye-sensitized solar cells (DSSCs) was studied. The DSSCs with the TiO2:Nb2O5-coated photoelectrodes showed an increase in short-circuit current (Jsc) and open-circuit voltage (Voc), resulting in a power conversion efficiency of 10.37% compared to 7.90% for the reference cell with a TiO2-coated photoelectrode. The increase in Jsc was due to an improvement in the light harvesting and electron collection efficiency. The suppression of the charge recombination between the injected electrons and the I3− ions was found to increase the Voc value of the device with the TiO2:Nb2O5-coated photoelectrodes.