Studies Of The APCVD Preparation And Properties Of A New Type Low-E Glass With TiN Coating

Titanium nitride (TiN) is an advanced semiconductor material with outstanding physical and chemical properties,such as high thermal conductivity, resistance to corrosion,high mechanical hardness, low electrical resistivity and perfect optical properties in visible and infrared regions. Because of these properties,TiN has been studied extensively. It has already used as a gold substitute for decorative coatings and as a wear-resistant coating on tools. In this thesis,TiN films were studied as a new low emission coating films because of their low electrical resistivity, outstanding optical properties like noble metallic films(Au, Ag). And for thin TiN films, they were semitransparent in visible region and high reflectance in infrared region. At the same time, a acomprehensive introduction of energy saving coating glass, especially low emission(Low-E) coating glass has been given including the development, energy saving characteristic, types and preparation methods.In this paper, studied as low emission coating films, TiN films were deposited on the glass substrates by atmosphere pressure chemical vapor deposition(APCVD) method under low temperature, using TiCl4 and ammonia as precursors, N₂ as carrier gas. The films were characterized by means of XRD, SEM, TEM, XPS and UV-VIS-NIR spectroscopy and so on. It has been studied synthetically that the relationship between the structure of TiN films, composition, photoelectrical properties and the deposition parameters such as the substrate temperature, deposition time, density of TiCl₄ and density of ammonia. All films prepared by this method are polycrystalline films with NaCl type structure. With the increasing of the substrate temperature, deposition time and the content of reactant, the thicker film can be deposited, which benefit the crystallization of TiN crystals. But too high thickness and high density of TiN films will do harm to the smoothness of film surface with impurity deteriorating the crystallization.A detailed analysis of the electrical properties of TiN films has been carried out in order to investigate the preparation parameters influences on the films. It showed that the conductive mechanics was like metal's. So its electrical properties was dependent on the microstructure of TiN film and the growth conditions of TiN film. And there were two factors to increase the electrical resistivity. One was cavity, and the other was impurity(especially oxygen). Both were effective scattering center. Excessive impurity and cavity will lead to the impurity scattering of electron. Moreover, The infraredreflection rely much on the carriers concentration and Hall mobility in the films. Improving the carriers concentration and Hall mobility, decreasing the sheet resistance will enhance of the infrared reflection of the TiN films.The result showed that the sheet resistance of TiN films is 34. 5 , the tansimittance of TiN films is 65% in visible region and the infared reflection of TiN films is 60%.Based on these above, it is possible to regard TiN films as the new type of low emission coating films. The experimental results of optical properties and chemical stability show that the glass have improved its thermal insulation property and lead to energy saving ability. More than that, the visible transmission and reflection of this glass have been optimized.