Highly Water-Repellent and Anti-Reflective Glass Based on a Hierarchical Nanoporous Layer

Optically anti-reflective and water-repellent glass is required for solar cell covers to improve power-generation efficiency due to transparency improvement and dirt removal. Research has been conducted in recent years on technologies that do not use fluorine materials. In this study, we focused on the anti-reflective properties and microstructure of hierarchical nanoporous layer (HNL) glass and used it as a substrate. As a result, we have achieved both strong anti-reflectivity and high water repellency on HNL glass by coating polydimethylsiloxane (PDMS) using baking and thermal chemical vapor deposition (CVD). The surfaces showed a significantly higher sliding velocity of water droplets than the PDMS-treated material on the flat glass plate. They also showed such water repellency that the droplets bounced off the surface.