Self-Cleaning, Superhydrophobic, and Transparent Silicone/Nanosilica/Silicone Coating: Implications for Photovoltaics

As photovoltaic power generation increasingly becomes a vital component of renewable energy, solar panels installed outdoors are prone to efficiency loss due to obstructions such as dust and bird droppings. To address this issue, this study presents a transparent superhydrophobic coating with exceptional self-cleaning properties. Relying on its micro/nanoscale rough structure and low surface energy, the coating enables water droplets to easily remove surface contaminants, thereby maintaining the cleanliness of solar panels and preserving their power generation efficiency. The challenge in developing such coatings lies in harmonizing their hydrophobicity, transparency, and durability─qualities that often have competing demands. Drawing inspiration from the sandwich structure, we designed and manufactured a superhydrophobic transparent coating with a resin/nanosilica/resin configuration. This was achieved through a simple dip-coating technique, resulting in a coating with an average water contact angle of 152.5° and a rolling angle of less than 1°. The silica-based nanostructure not only provides an antireflective effect but also enhances the coating’s light transmittance by nearly 3% compared to untreated glass. The silicone resin in the coating plays a dual role: it ensures the robust adhesion and stability of the silica, contributing to the coating’s durability, while maintaining a low surface energy, which is essential for the coating’s superhydrophobic properties and its remarkable self-cleaning ability. The sandwich-structured coating effectively reconciles seemingly conflicting properties, ultimately forming a high-performance superhydrophobic transparent coating with excellent comprehensive characteristics. This demonstrates tremendous application potential in photovoltaic encapsulation glass, automotive windshields, optical detectors, and architectural glazing systems.