Porous SiO2 antireflection film with high UV resistance

Sol-gel is one of the most economical methods to prepare antireflection films, but the low ultraviolet radiation-resistance (UV-resistance) of the sol-gel film limits its applicability in the solar industry. A SiO 2 antireflection film was prepared with sol-gel method with phenyl salicylate (PS) as the porogen. The effects of the PS addition were investigated on the microstructure, optical property and UV-resistance of the film. When the addition of PS is 1.20 g, the refractive index at 550 nm is 1.30, and the maximum transmittance is 96.30 %. The average transmittance within the 400–1100 nm range reaches its peak at 92.85 %, which is 4.35 percentage points higher than that of the blank glass. In addition, the film without PS has an average transmittance of 91.00 % after 5000 equivalent solar hours (ESHs) UV irradiation, decreasing 1.07 percent point, and has a pencil hardness of 5 H and an adhesion of grade 2 of the tape-tearing method. However, the film with 1.20 g of PS still has an average transmittance of 92.15 % after 5000 ESHs UV irradiation, decreasing only 0.7 percent point, and has a pencil hardness of 7 H and an adhesion of grade 1 of the tape-tearing method.