Preparation of SiO2 Film with High Hardness and Antireflection with AEO

To improve the efficiency of solar cells, antireflective films require not only high optical properties but also high mechanical properties. The antireflective films were prepared by tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) as precursors and fatty alcohol polyoxyethylene ether (AEO) as the porogen. The microstructures, optical properties, and mechanical properties of the prepared antireflective films were examined. The results indicated that the AEO volume ratio had an obvious effect on film porosity, refractive index and average transmittance. With the increase of AEO content, the film’s porosity and the average transmittance firstly increased then decreased, the refractive index firstly decreased then increased in the wavelength range of 400–1100 nm. In the meanwhile, both the film’s surface hardness and adhesion strength increased with the increasing of the AEO addition. When the volume ratio of AEO is 45%, the porosity of the film is 48%,the refractive index value for 550 nm wavelength is 1.26and the maximum transmittance is 98.50%.The highest amount of light passing through a material, also known as transmittance, is recorded at an average of 91.98%within the wavelength range of 400–1100 nm, which is 4.64%higher than that of blank glass. In addition, the hardness of the film reaches the highest level for soft films 9H, and its adhesion strength also reaches the highest level of the tape method, 0 grade.