Study On Preparation Of Infrared Reflective Thin Films

The merits and demerits of several kinds of infrared reflective films were analyzed and compared on the discussion about the origin and development of infrared reflective films. Sol-gel method was chose to make the basis films: SiO₂ and TiO₂ thin films, which were respectively used as a low reflectivity index media and a high reflectivity index media.XRD,SEM and SP(spectroscopic ellipsometer) were used to measure the samples. The results show that the TiO₂ thin film is anatase when heated at 500℃and becomes rutile when heated above 700℃.The size of crystallites is approximately 60-100nm. The thickness of single layer TiO₂ thin films is approximately 60nm The SP results reveal that the refractive index and the extinction coefficient of TiO₂ thin films in wavelength more than 800nm are about 2.09-2.20 and 0.026, respectively.The thickness of single layer SiO₂ thin films is about 456nm. And its refractive index is about 1.28 in visible spectrum, which increase smoothly with the decrease of the wavelength and become 1.31 at 250nm wavelength.An infrared reflective film is designed by self-program software on the basis of the data obtained by the experiments. The result achieved is a infrared reflective film of an average reflective index of 97.282% between 867nm and 1614nm.