Research on Contamination-Resistant SiO2 Optical Thin Films in a Vacuum Environment

Abstract

The Contamination resistance of SiO2 optical films prepared by using sol-gel method was investigated and improved in this research. FDTS (1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane) was used to modify SiO2 thin films. Fourier Transform Infrared Spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the components on surface of the SiO2 thin films. The optical properties and hydrophobicity were also measured. The results show that the SiO2 thin film modification with FDTS causes −OH groups to be replaced by organic groups containing fluorine. The transmittance peak of SiO2 thin film changes, and the surface contact angle of water droplets on the SiO2 film increases from 35° to 107° after surface modification with FTDS. After the SiO2 thin films had been put in a vacuum environment for 24 hours, the peak transmittance of the modified SiO2 film under the same conditions is reduced to 0.14%, which is less than 3.17% of the unmodified film. The peak transmittance of the modified SiO2 thin films is also improved.