Highly transparent, superhydrophobic, and durable silica/resin self-cleaning coatings for photovoltaic panels

Superhydrophobic coatings with unique self-cleaning phenomenon and have been studied in the fields of photovoltaics, concrete, windows, vehicle housings, and so on. However, obtaining self-cleaning coatings with excellent performance through a simple process and at a low cost is a difficult challenge. In this study, a simple dip-coating process was used to prepare a highly transparent superhydrophobic self-cleaning coating, with a bilayer structure consisting of a hexamethyldisilazane-modified silica antireflective buffer layer and an epoxy-modified silicone/fumed silica superhydrophobic surface layer. Due to the addition of the buffer layer, the structure of the coated surface is more regular, resulting in the coated glass having a transmittance 4.3% higher than the bare glass and achieving a static water contact angle of 155.1° and a sliding angle of 0.1°, demonstrating excellent self-cleaning performance. The cross-linking curing of the silicone resin allows the coating to demonstrate stability in a variety of extreme environments. Therefore, the use of coated glass to encapsulate photovoltaic cells resulted in a significant increase in photovoltaic conversion efficiency, and the cell performance remained unchanged after contamination and self-cleaning procedures. This low-cost strategy is expected to increase photovoltaic cell power generation and address the problem of degraded device performance due to surface contamination.