Mechanically robust and self-cleaning antireflective coatings for photovoltaic modules

Abstract

As the conversion efficiency of solar cells approaches its theoretical upper limit, the importance of photon management in enhancing photovoltaic modules performance becomes paramount. One promising approach involves the application of antireflective coatings to the surface of the photovoltaic glass to improve its transmittance. However, balancing mechanical durability, self-cleaning characteristics, and optical performance for photovoltaic applications remains challenging. This study focuses on synthesizing a composite coating through the sol-gel method, aiming to achieve high optical transmittance and superior mechanical properties. Hollow silica nanoparticles (HSN) are employed to achieve a reduced refractive index, while a composite sol of zirconium dioxide (ZrO2) and titania (TiO2) is utilized to enhance mechanical strength and hydrophilicity. The prepared composite coatings demonstrate notable improvements, with the photovoltaic transmittance (TPV) increasing from 88.31 % to 94.03 % in the 300–1100 nm wavelength range, with peak transmittance reaching 98.01 %. Additionally, the coatings exhibited a pencil hardness rating of 3H alongside exceptional abrasion resistance, affirming their potential for enduring practical deployment. When compared to uncoated glass, modules integrated with these composite coatings showed a significant increase in short-circuit current density (JSC) by 1.28 mA cm-2 and in photoelectric conversion efficiency (PCE) by 0.70 %. These results highlight the composite coatings' capacity to enhance the conversion efficiency of photovoltaic modules significantly. By attempting to prepare anti reflective coatings with high mechanical strength and self-cleaning properties, this study is expected to make a valuable contribution to the advancement of sustainable and durable solar cell technology.