Self-sustaining antifouling coating for underwater solar cells

Abstract

If not protected, underwater solar cells are encrusted with biological organisms, such as algae and barnacles, which lower the electrical or operational efficiency and are expensive to remove. We engineered a self-sustaining antifouling coating using ultra-low concentrations of nano-sized, seawater-soluble pigments, specifically cuprous oxide (Cu2O) and zinc oxide (ZnO), combined with an organic booster biocide and a fast-polishing binder material. This coating maintained high levels of visible light transmission for three months in tropical seawater without requiring human intervention, such as mechanical cleaning. Field tests demonstrated the coating's effectiveness in preventing biofouling, while preserving transparency. We anticipate that these self-sustaining antifouling coatings can be applied to thin, transparent, and interchangeable substrates for continual replacement on solar-powered autonomous underwater vehicles or solar cell platforms, thereby ensuring long-term operational efficiency.