Effect of Polymeric p-Type Semiconductor on Photovoltaic Properties in Dye-Sensitized Solar Cell.

A hole formed in photo-excited dye molecule under illumination is transferred to cathode with iodine ion in electrolyte solution in the dye-sensitized solar cell developed by M. Grätzel and the conductivity of the iodine ion affects conversion efficiency of the cell. In this work, effect of the polymeric p-type semiconductor on the hole transferability is investigated. PEDOT:PSS and P3HT were used as the p-type semiconductors. Dye-sensitized solar cells were composed of aluminium plate, Nb-doped TiO2 layer adsorbed with TCNQ, the electrolyte solution containing iodine ions, and ITO glass plate. In a solid-type cell substituted the electrolyte solution with the p-type semiconductor, photocurrent was not generated. The photocurrent was generated in the solar cell by introducing the electrolyte solution containing iodine ions between the ITO glass and the p-type semiconductor formed on the dye-adsorbed Nb-doped-TiO2 layer or between the dye-adsorbed Nb-doped-TiO2 layer and the p-type semiconductor formed on the ITO glass. The conversion efficiency increased with the introduction of the p-type semiconductor such as PEDOT:PSS, compared only with the electrolyte solution. The p-type semiconductor containing iodine ions promote the hole transfer of iodine ion, compared with that in the electrolyte solution. [ABSTRACT FROM PUBLISHER]