Highly Transparent and Superhydrophobic SiO₂ Coating with Nanoscale Structures by One-Step Spraying Technology for Applications as Self-cleaning Coatings

Given the urgent need for self-cleaning capabilities in solar cells across various applications, achieving a high-performance self-cleaning coating through simple construction and low cost remains a challenge. This study successfully developed a highly transparent superhydrophobic self-cleaning coating by using a straightforward one-step spraying process with hydrophobic vapor-phase SiO2, silicone resin, and epoxy resin. The coating features nanoscale structures that enhance both its transparency and superhydrophobic properties by creating a rough surface at the microscopic level. The coating in this study has a maximum static contact angle of 160° and a roll angle of 1°. Compared to bare glass, the coated glass showed a 3% increase in light transmittance, resulting in a 1.24% improvement in the encapsulation efficiency of crystalline silicon cells. Even after five cycles of 400 mesh sandpaper polishing or 30 days of exposure in an open outdoor field with a total of over 140 h of sunlight and more than 50 mm of rainfall, the superhydrophobic properties, with a rolling angle of 1° for various water-based solutions, were still maintained. Consequently, this low-cost and easily prepared superhydrophobic coating demonstrates excellent self-cleaning capabilities while enhancing the power generation efficiency of solar cells. This technology holds great promise for widespread application in large-scale photovoltaic power plants and building-integrated photovoltaic systems, contributing to the proliferation of green energy and environmental protection.