Co-sensitization Promoted Light Harvesting for Dye-Sensitized Solar Cells

Co-sensitization of two sensitizers on core/shell TiO2–Nb2O5 with Ta2O5 scattering layer photoanode arranged in different sequences are investigated for application to dye sensitized solar cells (DSSCs). The co-sensitization of N719/Coumarin and CdS–CdSe quantum dots/Coumarin exhibited enhanced photovoltaic performances for the pertinent cells compared with the cell made from corresponding individual sensitizers. In the present investigation, co-sensitization by N719/Coumarin showed better photovoltaic performance and have the power conversion efficiency (PCE) of 9.9 % while the performances of cells with the individual sensitizers are 8.2 % (N719) and 6.9 % (Coumarin) respectively. The PCE of DSSC with CdS–CdSe/Coumarin co-sensitization is found to be 8.7 % whereas the performances of DSSCs with the individual sensitizers are 4.5 % (CdS–CdSe) and 6.9 % (Coumarin) respectively. These results indicated that the co-sensitization of sensitizers promoted the light harvesting efficiency of DSSCs as compared the cells with the consequent individual sensitizers.