Preparation Of Transparent Conductive Thin Films And Their Fine-Patternings

Antimony doped tin oxide(ATO) and Indium tin oxide (ITO) thin films have been prepared by a sol-gel process using inorganic metal salts as precursors. The effects of heat-treatment atmosphere, temperature, time and dopant content on the electrical and optical properties of thin films were investigated. The fine patternings of the ATO films were fabricated by chemical modification and sol-gel method. The results are listed as follows:(1) SnCl2 2H2O and absolute ethanol were refluxed at 80℃ for about 2 hours. SbCl5 was chosen as the dopant source. Then yellowish antimony doped tin oxide(ATO) sol was prepared, which was transparent and stable. The chemical change didn't happen and the sol can be used as normally when the sol was deposited for 1 year at room temperature.(2) In(NO3)3 was dissolved in acetylacetone in the mol ratio of l:3.They were mixed for about 3 hours to obtain acetylacetone salts. Then glycol methyl aether was added in the ratio of 1:40 to obtain indium oxide sol. SnCl4 was dissolved in glycol methyl aether and then added into the indium oxide sol to prepare transparent and stable ITO sol. This sol was good for the preparation of the thin films.(3) ATO thin films showed the lowest resistivity of 1.37xl0-Ωcm at antimony dopant of 4 %,heat-treatment at 480℃ in air for 5 minutes. The average spectral transmittance was 78.66% in the wavelength rage of visible spectrum on the glass of 93.37% average transmittance. ITO thin films have the lowest resistivity of 2.4x10-3Ωcm at tin dopant of 7%,heat-treatment at 800℃ in vacuum atmosphere for 15 minutes. The average spectral transmittance was 85.13% on the quartz glass substrate of 92.6% average transmittance. This is to say ITO thin films have the better conductivity and transparency than ATO thin films.(4) Photosensitive ATO sol has been prepared using three methods. The gel by sodium alcoholate method, added benzoylacetone, have the obvious UV absorption peaks at 265nm and 337nm respectively. When the gel was placed in air, the chelate didn't have change. The absorption peak decreased until disappeared when the films were irradiated by the ultraviolet light with the relevant wavelength, which indicated that the films were obviously photosensitive. The fine patterning has been fabricated fromphotosensitive gel film.