Superhydrophobic coatings based on pseudoboehmite nanoflakelets for sustainable photovoltaic energy production

Scalability, transparency, and robustness are the bottlenecks for superhydrophobic (SH) coatings, which restrict its use in commercial solar panel applications. Herein, a systematic approach is demonstrated to upscale the SH coating consisting of hierarchical pseudoboehmite nanoflakelets on solar cover glass of photovoltaic (PV) panels using a custom-made large area wire-bar coater. The pseudoboehmite nanoflakelets manifested an ultrahigh water contact angle (CA) of >175° and near-zero roll-off angle (RA) of <1°. The pseudoboehmite hierarchical nanoflakelets aided in augmenting the antireflective property with a superior optical transmittance of >93% in contrast to the uncoated glass (89%) with improved solar performance because of its subwavelength nanostructures. The nanoflakelets exhibited enhanced conversion efficiency compared to uncoated glass, resulting in 13.2% enhancement because of the superior light trapping capability over the entire visible region. Significantly, the SH surface sustains the efficiency (99.7%) after exposure to the dust particles because of the excellent self-cleaning characteristics of the nanoengineered surface. The present work also envisions a comprehensive study of the performance of the SH coating toward mechanical and chemical stability. The proposed work paves a pathway in harvesting sustainable solar energy for PV systems because of its potential advantages of self-cleaning properties, scalability and low cost.