Preparation,structures And Properties Of SnO₂:F And TiO₂:Nb Thin Films

Transparent conductive film is one of the most important areas of the material science.Now,transparent conductive oxide films have become an indispensable component in the industrial production and daily routine,and also become a necessary materials for the development of high technology.The metal oxide thin film,due to its low resistivity and high transmittance to the visible light,has been widely used in solar cells,protective coating,the light pervious electrodes,and the gas sensor aspects.Although ITO metal oxide film,which has excellent properties and its high quality film can be produced now,has been widely used,but its main component In is very lacking in the nature.So,to explore new kind of transparent oxide conductive film will produce a more profound significance.In this paper,we use the sol-gel method to prepare the film,i.e.we use Tin?II?chloride dihydrate?SnCl₂·2H₂O?,Ammonium fluoride?NH₄F?,Tetrabutyl titanate?Ti[O?CH₂?₃CH₃]₄?and Niobium chloride?NbCl5?as the main raw material,and ethyl alcohol as the solvent to prepare the sol of SnO₂:F and TiO₂:Nb.Then,by using the dip-coating method and the process of heat treatment,to get the SnO₂:F thin film on glass substrate and TiO₂:Nb thin film on SnO₂/glass substrate.By using X-ray powder diffraction?XRD?,scanning electron microscope?SEM?,X-ray photoelectron spectrometer?XPS?,UV-Vis spectrum and four point probe method to study the structure,optical properties,and electrical properties of these thin films.The main results are as follows:1.To the film of SnO₂:F?FTO?,the doping concentration of F and the temperature will produce a very great effect on the electrical conductivity of the film.The suitable F-doping concentration can significantly improve the conductive performance of the film while the light transmittance can reach 70%;excessiveF-doping will decrease the conductivity and the light transmittance greatly.Higher temperature will improve the conductive property of the film within limits;however,it has a little effect on the light transmittance of the film.In our research,when F-doping concentration is 20%,the heat treatment temperture is 500?,the best conductive performance of FTO film has been got,and the resistance and resistivity values are 15?/? and 6.11×10-4?·cm respectively,and the visible light transmittance can reach 71%.2.In the preparation of TiO₂:Nb thin film,we use SnO₂/glass as a substrate.The purpose is to solve the TiO₂ directly deposited on glass substrates is amorphous crystal structure.It is found that Nb-doping concentration,heating temperature and time,the thickness of the film will produce a certain effects on the optical and electrical properties of TNO film.In our research,when Nb-doping concentration is 6%,the film thickness is 5C?5 layers of TNO film?,the calcination temperature is 500?,and the heating time is 60 min,the conductive performance of TNO film is better,and its resistance and resistivity are 1.40×103?/? and 3.36×10-2?·cm respectively,and its visible light transmittance can reach 70%-75%.