Room-Temperature Fabrication of Dual-Functional SiO2/TiO2 Coating for Photovoltaic Efficiency Enhancement: from Laboratory Development to Field Validation

Dust accumulation on photovoltaic (PV) modules remains a critical challenge that severely reduces their lifespan and energy output efficiency in practical applications. To address this issue, a SiO ₂ /TiO ₂ (ST) coating was fabricated at room temperature, integrating the dual properties of antireflectivity and self-cleaning to simultaneously enhance light harvesting and mitigate dust adhesion. The ST coating achieves a 3.35% increase in optical transmission within the visible spectrum and demonstrates practical durability with only a 0.1% reduction in performance after 400 brushing cycles. The self-cleaning capability of the ST coating is attributed to its unique dual function of antistatic and superhydrophilic, as evidenced by a surface resistivity of 10 ⁸ Ω and a water contact angle of 5°, respectively. For practical evaluation, the as-developed coating was applied to a rooftop distributed solar power plant in Xi’an, China. Based on a five-month successive field investigation, the PV arrays treated with ST coating showed an average efficiency gain of 3.36% compared to uncoated modules, with monthly efficiency improvements ranging from 2.07–6.74%. These findings highlight the economic potential and environmental benefits of as developed ST coating, emphasizing its role in enhancing the sustainability of solar energy systems.