Mixed Dyes for Dye-sensitized Solar Cells Applications

Background: Energy crisis is a vital issue worldwide and it will be increased tremendously in future. Alternative energy sources have been sought for the betterment of the future world. Solar energy is an alternative energy resource with plenty of opportunities. To make user- friendly and cheaper solar cells, dye-sensitized solar cells are tried to develop in this aspect. Objective: Single dye is not good enough to capture a wide range of solar light. The blending of different dyes is an alternative approach to harvest a wider range of solar lights on solar cells. Here, N719 and IR dyes were utilized to get UV-VIS and NIR ranges of solar lights in dye-sensitized solar cells. Methods: Dye-sensitized solar cells (DSSCs) were fabricated by using mixed dyes with various combinations of N719 (dye A) and IR dyes (dye B). The mixed dyes solutions were adsorbed on titanium dioxide (TiO2) and revealed significant light absorption & photosensitization compared with the individual dye solutions. The DSSCs fabricated with more percentage of IR dyes exhibited the best sensitization and broader spectrum. Results: The light absorption spectrum of the blended dyes solutions was confined peaks resultant of both N719 and IR dyes. The maximum efficiencies of 7.91% and 7.77% were obtained with 70% and 80% of IR dyes, respectively. Conclusion: Both N719 and IR mixed dyes solar cells were fabricated successfully for the first time. The relevant reasons behind the working of N719 and IR mixed dyes solar cells have been discussed. It was also noted that only IR dyes sensitized cells did not function under the simulated sunlight.