Dye-sensitized solar cells as promising candidates for underwater photovoltaic applications

Harvesting solar energy using photovoltaic (PV) cells is the simplest, efficient, and reliable approach to power marine electronics. Installing PV above or under water provides cooling and cleaning to sustain the power conversion efficiency. Previous work on commercially available silicon-based PV quantified the performance of PV with different submerged environments and showed promising results in harvesting available underwater solar energy. Subsequent, theoretical studies point to enormous potential of using wide-band-gap PV in underwater conditions. With this motivation, herein for the first time, a dye-sensitized solar cells (DSSCs) employing wide-bandgap ruthenium sensitizers (1.8 eV) have been tested under submerged conditions. The DSSCs were characterized under submerged conditions up to 20 cm. Four replicates provided data detailing DSSCs potential for underwater PV applications when compared with the previously collected data for monocrystalline, polycrystalline, and amorphous silicon PV. Although the light intensity under water decreases with an increase in depths, the rate of decrease in power output for DSSCs was only 40.68%, which was less than the traditional monocrystalline and polycrystalline silicon PV by approximately 20-25%. Also, compared with amorphous silicon PV, DSSCs showed a slightly better performance by 2-3%, clearly displaying the capability of DSSCs to harvest indirect/diffused lights in comparison with the conventional PVs. Compared with the conventional PVs, indigenously fabricated DSSCs showed tremendous relative increase in performance in underwater conditions. Further work is underway to further optimize DSSCs even though it can be concluded that with added advantages of simple fabrication process and cost-effectiveness, DSSCs have enormous future potential for underwater PV applications.