Highly transparent, self-cleaning, and UV-shielding composite coating: When eco-friendly waterborne omniphobic surface cooperates with quantum dots

Solar energy is an inexhaustible carbon-free source, and solar cells are invaluable enablers for achieving carbon neutrality ; however, the surface contamination on the glass of solar cells poses a formidable obstacle to maintaining a high power conversion efficiency . Existing self-cleaning coatings for combating surface contamination generally lack the highly comprehensive properties required for applications in real-world conditions. Herein, eco-friendly, highly transparent, waterborne omniphobic Si 2.5 WPA/AmZnO@SiO 2 coatings were developed by the ingenious design of polydimethylsiloxane-grafted waterborne polyacrylate (Si x WPA) and (3-aminopropyl)triethoxysilane-modified-SiO 2 encapsulated ZnO quantum dots (AmZnO@SiO 2 ). The enriched PDMS flexible chains on the coating surface overcame the energy barriers for moving liquids, and the AmZnO@SiO 2 inside absorbed and scattered UV rays, which synergistically endowed the coating with self-cleaning and UV-shielding properties. Importantly, after the self-cleaning procedure, the light transmission of dust-contaminated glass and short-circuit current density of corresponding solar cells could be restored to 99.78 % and 97.77 % of initial metrics, respectively. Furthermore, the commonly ignored self-cleaning mechanism was investigated and proposed: the coating weakened the adhesion of dust particles and utilized the drag force generated during liquid slip to achieve self-cleaning. The coating also showed good UV/humidity/thermal stability and mechanical strength , providing a design blueprint for outdoor optical device protection.