Hydrophobic antireflective coatings based on the synergistic effect of hollow and solid silica for application in photovoltaic modules

Photovoltaic glass coatings with multiple functions, such as strong broad-spectrum antireflectivity, effective self-cleaning, anti-abrasiveness, stability, and durability, have great potential for improving and ensuring the outdoor operation of photovoltaic modules . In this study, alkali-catalyzed hollow and solid silica nanoparticles were mixed at controlled ratios by sol-gel method, and the resulting solution was modified with HMDS to improve hydrophobicity , and obtain refractive indices ranging from 1.45 to 1.13. Subsequently, based on the principle of gradient refractive index, a trilayer hydrophobic antireflective (TLHA) coating was developed, comprising a top layer (n = 1.13), a middle layer (n = 1.27), and a bottom layer (n = 1.44). The TLHA coating exhibited an average transmittance of 97.77 % in the wavelength range of 380–1800 nm, with a peak transmittance of 98.97 % at 572 nm, and a hydrophobic contact angle of 144°. Additionally, after 144 h of thermal cycling and 600 abrasion cycles, the average transmittance of the TLHA coating decreased by 2.43 % and 1.63 %, respectively, in the 380–1800 nm range, and the coating's pencil hardness reached 5 H. And further application results showed that the crystalline silicon micro-modules with the TLHA coating could exhibit a 7.63 % and 5.24 % increase in J sc , as calculated from EQE and J-V curves respectively, and a 5.34 % increase in PCE , compared to modules without the TLHA coating. These results highlight the extensive applicability of the TLHA coating in enhancing outdoor photovoltaic operation efficiency, durability, and wear resistance.