Study On The Synthesis Of Indium Alkoxides And Stannic Alkoxides And The Preparation Of Sol-Gel-Derived ITO-films By Dip-Coating

Metal alkoxides are varieties of important compounds. A brief account of the methods generally employed for the synthesis of metal alkoxides has been presented in this paper. After listing the typical. physical and chemical properties, their applications are briefly reviewed. Indium alkoxides and stannic alkoxides are very useful fine chemicals, which may be the precursors used for the preparation of sol-gel-derived ITO-layer. At fist, anhydrous indium trichloride has been prepared by the reaction involving metal indium with chloride gas. Then Used item as raw material, the synthesis methods and the technical conditions of indium alkoxids have been studied in detail. Meanwhile, stannic alkoxides have been prepared by reacting freshly anhydrous stannic chloride with the alcohols and ammonia or sodium alkoxides. The results have shown that anhydrous indium trichloride and stannic tetrachloride are good raw materials for the synthesis of their alkoxides and these reactions may be influenced by many factors, such as solvation, reaction condition, and method of preparation. Due to indium and stannic having different electronegativity values, the ammonia method is more suitable than sodium alkoxides method for preparing stannic alkoxides, while the sodium alkoxides method is more suitable for synthesis of indium alkoxides. Furthermore, Indium acoholates mCi3 2ROH and its alkoxides In(OR)3 [R Et,Pr?Bu^] and stannic acoholates SnCl^OR4. nROH and stannic alkoxides Sn(OR)4 [R=Et,PrI,Bu1; x²,3; w2,3] have been isolated and some of them have been characterized by JR spectroscopy and chemical analyses. Moreover, the yields of preparing these alkoxides are above 70%. On the basis of these experiments, the reactions involving tetrahydrous indium trichloride with the acohols under special conditions have been investigated and indium alkoides have also prepared by use of this special method, whose yields may be up to 80%. Indium-tin-oxide (ITO) film is an excellent photoelectric material, which has interesting n-type semiconducting properties. In this study, the ITO-films were prepared by a new method: using indium and stannic alkoxides prepared by above experiments as precursor, thexerogei films were prepared on glass through polymeric sd route by dip-coating. Their sheet resistances were respectively 10 and 1000 fI ,and their film thicknesses may be up to 8Onm.