Development of anti-reflective coatings with photocatalytic and hydrophobic self-cleaning property for solar cells

Accumulation of dust and dirt on the surfaces of photovoltaic modules significantly diminishes power generation efficiency, posing a formidable challenge. To address this limitation, we engineered a multifunctional film integrating anti-reflective and self-cleaning properties. The innovative film was fabricated by applying two functional layers on a glass-substrate. The bottom layer was created using a hydrophilic silicon dioxide (SiO₂) based gel, into which titanium dioxide (TiO₂) nanoparticles coupled tungsten nitride (WN) nanoparticles (denoted as TiO₂@WN) were added as an effective photocatalytic component. The top layer consisted of a hydrophobic dimethyl silicone oil (PDMS) modification. The optimized SiO₂/WN@TiO₂/PDMS (SOTWH) coating demonstrated a 2.16 % increase in average transmittance (92.83 %) compared to bare glass (90.67 %), and its mechanical robustness was evidenced by a Vickers hardness of 437.08 N/mm². The SOTWH film also exhibited superior photocatalytic degradation efficiencies of 66 % tetracycline hydrochloride and 48 % rhodamine B removal within 120 min, respectively. Synergistic surface engineering endowed the SOTWH film with a water contact angle of 104.5°, enabling efficient contaminant removal through rain-driven shear forces. This dual-mode self-cleaning mechanism combined photocatalytic decomposition and hydrophobic dust repulsion, outperforming the commercial anti-soiling coatings. The developed film system presents a technologically viable solution for sustaining photovoltaic performance through optically active, durable, and environmentally responsive surface engineering.