Study Of The Preparation And Optical, Electrical Properties Of TiN Coating Glass

Energy crisis is gaining more and more attention globally, even becomes a strategic issue of a country. To save limited energy sources which have been found is an available means adopted by countries on after another. At present, the energy-saving glasses applied in architecture mainly include low emissivity (low-e) glass and solar control glass. Low-e glass can reflect infrared radiated by things in the house by means of blackbody radiation, used extensively in cold areas in the winter to preserve heat and reduce energy consumption. Soloar contol glass can reflect visible light and near-IR from the sun under the condition of supplying enough light, applied mainly in hot areas in the summer to be cool and reduce the burden of air-conditioner. In addition, Titanium nitride (TiN) has thermal stability, good diffusion barrier properties and low electrical resistivity. TiN films exhibit high reflectivity in the IR region which is very important in energy saving coating glass industry. The thesis supposes the subject of TiN films as low emittivity films, based on a comprehensive introduction of fundamentals of energy saving, parameters of evaluating properties, preparation methods of low emittivity films, as well as basic physical properties, especially excellent electrical property of TiN films. A new type of energy-saving coating glass with low-e and solar control functions can be expected. TiN films were deposited on glass substrates by atmospheric pressure chemical vapor deposition (APCVD) using titanium tetrachloride (TiCl₄) and ammonia (NH₃) as reactants, nitrogen (N₂) as protective atmosphere and carrier gas in this paper. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersion spectroscopy (EDX), four-point probe method, optical spectroscopy and Fourier Transform Infrared Spectrometry (FTIR) were employed to study the crystallinity, microstructure, surface morphology, electrical and optical properties, respectively.The corelationship between these properties and the effect of deposition parameters such as the deposition time, the flow rate of TiCl₄, and the deposition distance on them were synthetically discussed.The results showed that the deposited TiN films exhibited a preferred (200) orientation with NaCl structured. With the increase in the deposition time, the crystallinity of films enhanced, the particles growing, the films tended to be thicker, denser and more continuous. Thus the reflectivity in the near-infrared region increased, due to the decrease in the electrical resistivity originated from higher mobility and concentration of the carriers. The effects of the changes of the flow rate of TiCl4 on varieties of properties of are similar with the deposition distance, the fittest values could be obtained. The N and Ti atomic ratio determined the concentration of carriers in films which influenced the optical properties. In the substoichiometric range the electrical and optical properties of films improved with the increase in the ratio.The optical properties of the most satisfactory TiN film sample are as follows: the average reflectivity in the visible region was less than 15%, the reflectivity in the near-IR and IR regions were more than 55% and about 80%, respectively. It shows that the TiN coating glass has the functions of low emissivity and solar control. But the transmittance in visible region is a little low. We tend to improve the equipment to prepare thinner films, which can enhance the transmittance of films. TiN coating glass can be expected to be a type of energy-saving coating glass with high efficiency.