Fabrication of Highly Efficient Plastic-Substrate Dye-Sensitized Solar Cell Sub-Modules by Room-Temperature Roll Press Method

29th European Photovoltaic Solar Energy Conference and Exhibition; 1519-1522
The fabrication of highly efficient plastic-substrate dye-sensitized solar cell (Pla-DSC) sub-module was conducted by using the roll press method at room temperature. As a result, a 5cm-square Pla-DSC sub-module with 6.5 % efficiency, which is one of the best efficiencies among Pla-DSC sub-modules, was developed. A newly developed light-scattering counter electrode composed of the TiO2 large-particle-layer over Pt sputtered Ti foil as well as the cosensitization of black dye and organic dye D131 was applied to improve the efficiency of 5mm-square Pla-DSC mini cell. The efficiency improved from 7.8 % up to 9.1 %, which is the world record among Pla-DSC mini cells. Then, a large-size TiO2 photoelectrode was prepared by the doctor blade coating of TiO2 paste and the following roll press at 100 MPa at room temperature. The exfoliation of TiO2 film from ITO/PEN substrate under the roll press was the problem to solve. A newly designed alcohol-mixture solvent for TiO2 paste suppressed the defoliation of TiO2 film from the substrate. In addition, the current-collecting Ag grid and its protecting layer on Ag grid against iodine corrosion were fabricated over the ITO/PEN substrate to improve the cell efficiency of Pla-DSC sub-module. A durable methoxy-propionitrile (MPN) electrolyte solution was utilized. Finally, a highly efficient and durable Pla-DSC sub-module was successfully fabricated.