Study And Preparation On TiN_x-SiO₂-Ag-SiO₂ Low-Emissivity Composite Thin Films

With the increasing demand of building energy saving, applications of low emissivity glasses in commercial and residential architectures are growing quickly. Recently the chemical and mechanical properties are introduced into low-E coatings, and a new kind of offline low-E glasses appeared, which can be manufactured at another place. While satisfying the transmittance of natural light, the traditional low-E glasses can save a lot of energy in air conditioning and house heating. Low-E systems based on silver films are the most popular in the world. Many kinds of dielectric materials are already exist, most of which are metal oxide, such as TiO₂, ZnO, SnO₂, and so on. In order to prevent oxidation, another metal thin film should be deposited on Ag thin film, which, however, may weaken the optical function of the coatings. And the traditional offline low-E glasses should be made into hollow glasses which cannot be reprocessed. However, the new offline low-E glasses have more advantages than the traditional ones, such as that it can be storied in the air for a long time in singles, and it can be manufactured at another place. Titanium nitride hard films have excellent physical and chemical properties, and silicon dioxide could enhance the Ag films with glass. In this paper, a new kind of TiN_x-SiO₂-Ag-SiO₂ coatings has been prepared.In this work, all films have been prepared by rf-magnetron sputtering, N₂ was the reaction gas. The films were tested by means of XRD, SEM, XPS UV-VIS-NIR spectroscopy, ellipsometer and so on.The results showed that the nano TiN_x film is amorphous with high visible transmission. The higher of the rate of N/Ti, the deeper of the color of TiN_x thin films, and the visible light transmittance becomes lower. The thicker of TiN_x thin film the better of the adhesion and corrosion resistance of the low-E film. While the thickness of TiN_x thin film is less than 5nm, the corrosion resistance of low-E film is not good. The thin film structure in this paper is as follows: (20nm)TiN_x-(20nm)SiO₂-(10nm)Ag-(20nm)SiO₂, the visual transmission of which comes to 78%, and the emissivity is about 0.11.