Preparation of SiO2 antireflection film with high hardness and adhesion by mPEG

Coating antireflection film on the surface of glass cover is one of the important methods to improve the photoelectric conversion efficiency of solar cells. Sol-gel method is suitable for low cost and large area preparation of antireflection film. However, most of antireflective films prepared with sol-gel have not enough good mechanical properties, and their applications are restricted. A porous antireflection film was prepared with sol-gel, where the polyethylene glycol monomethyl ether (mPEG) was used as the porogen. The effects of the mPEG additive amount were investigated on the microstructure and properties of the film. The results showed that the transmittance of the film (the coated glass) first increases and then decreases with the increase of the amount of mPEG. When the amount of mPEG is 0.6 g, the average transmittance of the film in the wavelength range of 380-1100 nm is the highest, higher than that of glass substrate by 4.2 percentage points. The adhesion of the film reaches grade 0 and the hardness is greater than 9H. The efficiency of monocrystalline silicon solar cells could be increased from 11.65% to 12.04%, by a relative increase of 3.35%