Sol–gel-derived bayberry-like SiO2@TiO2 multifunctional antireflective coatings for enhancing photovoltaic power generation

Multifunctional coatings with broadband antireflective, durable, photocatalytic , and self-cleaning properties can enhance photovoltaic (PV) power generation by reducing the cleaning frequency and surface light reflection of PV modules . However, such coatings must be cost-effective and maintain their functional integrity under harsh outdoor environmental conditions. In this study, bayberry-like SiO 2 @TiO 2 nanoparticles were prepared by a sol–gel method, and their synthesis procedure and SiO 2 /TiO 2 sol volume ratio were optimized based on the refractive index , transmittance distribution, and methylene blue degradation rate . Afterwards, three-layer gradient refractive index broadband antireflective coatings (TGBA) of the optimized SiO 2 @TiO 2 nanoparticles were simulated theoretically and systematically characterized by various experimental techniques. The average transmittance of TGBA-coated glass was 8.93% (380–1800 nm) higher than that of undipped glass, and the photocatalytic performance of TGBA was verified by studying methylene blue photodegradation . The self-cleaning performance of TGBA was assessed by outdoor exposure, multi-cycle ultraviolet (UV) irradiation, and dark storage. The durability of TGBA was evaluated by conducting hardness measurements , abrasion testing, thermal cycling, and damp heat tests . The external quantum efficiency and J–V curves of TGBA-coated PV mini-modules revealed that their short-circuit current densities and power conversion efficiencies were substantially higher than those of undipped modules. The proposed multifunctional coatings can enhance PV power generation in harsh environments.