Studies On The Preparation And Property Of ITO And AZO Thin Films Material By Sol-Gel Method

Transparent conductive oxide thin film is a kind of photoelectricmaterial which combining electrical conductivity and transparencyproperties of optical. It not only has high conductivity and hightransmittance in the visible light region scope, but also can reflect infraredlight, absorb ultraviolet light. Because of the excellent photoelectricproperties, it is widely used in the field of LCD monitor, anti-fog andanti-icing windows of cars and aircraft, solar cells, gas sensors, etc.Transparent conductive oxide thin films mainly include SnO2, In2O3, ZnOand the oxide doping system.There are many methods for the preparation of transparent conductiveoxide films，the magnetron sputtering method, vacuum evaporation coatingmethod, chemical vapor deposition law （CVD）, sol-gel method （Sol-Gel）,and spray thermal decomposition method etc. The magnetron sputteringmethod is mostly applied in the industrial, but this method has manydisadvantages which the equipment is relatively expensive, relatively highcost and a relatively low target utilization. The method of sol-gel has manyadvantages which a lower equipment costs, the process is relatively simpleand inexpensive raw materials, and in this method the film can also be alarge area of forming.The ITO films and AZO thin films were prepared on the glasssubstrates by sol-gel and rotating film method with InCl₃·4H₂O andSnCl₄·5H₂O、（CH₃COO）₂Zn2H₂O and AlCl₃6H₂O. Using X-raydiffraction, scanning electron microscopy, UV-Vis spectrophotometer andthe four-probe resistance tester to measure and characterize the componentsof an object, the morphology, the transmission spectrum and the squareresistance of ITO film and the AZO film, The effects of different heat-treatment temperature and time, different dopant solubility and coatinglayer on structure and photoelectric properties of ITO thin film and the AZOfilm were researched. Experimental results:（1） With the increasing of theheat treatment temperature, the crystallization characteristics of the ITO filmincreased evidently, the crystal structure also optimized well， thetransmittance of the film gradually increases, and at first the sheet resistancestraightly decreased then gradually increased, the best annealing temperatureis450°C. The AZO film crystallization characteristics became obvious,crystal structure gradually became completed, and the transmittance of thefilm gradually increased, the sheet resistance gradually reduced, the optimalannealing temperature is500°C.（2） transmittance of ITO film the firstincrease with increasing heat treatment time is reduced sheet resistance firstdecreased and then increased，the best annealing time is60min; with theincrease of the heat treatment time, AZO film transmittance reduced the leadin increasing, the sheet resistance first decreased and then increased, the bestannealing time is60min.（3） transmittance of ITO films decreases graduallywith the increase of doped tin content, sheet resistance decreases and thenincreases the best doped tin solubility of12wt%; AZO film transmittancereduced the lead in increasing the sheet resistance first decreased and thenincreased solubility of the best aluminum doped1at%.（4） As the coatingincrease in the number of layers, the transmittance of the ITO film isgradually decreased, the sheet resistance is gradually reduced the bestcoating stratum to6layers. The transmittance of AZO films graduallyreduce the sheet resistance is gradually reduced the best coating layers to8layers.According to the above the experiment and the experimental data showthat the optimal parameters on preparation of ITO film in the method of sol-gel: heat treatment temperature and time were450℃and60min; the dopedtin concentration of12wt%; coating layers6layers; preparation of AZOfilm parameters: heat treatment temperature and time were500°C and60minutes;1at%doped tin concentration; coating layers to8layers.