SYNTHESIS AND CHARACTERIZATION OF TIN VALERATE AND TIN OXIDE THIN-FILMS

Tin valerate films have been prepared by spincasting solutions produce d from the hydrolysis of tin(II) methoxide or tin(TV) isopropoxide in alcohol and valeric acid. Tin oxide films were made from tin valerate films using two methods: calcination at 400 degrees C in air and by ro om temperature hydrogen peroxide treatment. AU tin valerate and tin ox ide films are transparent and exhibit uniform adhesion to quartz subst rates. FTIR and XPS analyses indicate that the structure and compositi on of valerate films prepared from either alkoxide are similar despite differences in precursor oxidation state and concentrations of acid a nd alcohol used for the syntheses. Tin valerate films are comprised of an oxygen-tin polymer backbone coordinated with valerate ligands. Bot h monodentate and bidentate carboxylates are present, the former appar ently stabilized by hydrogen bonding with sorbed water. Quantitative X PS analysis indicates that valerate/tin and hydroxyl/tin ratios are 0. 26 and 0.55, respectively. This level of film carboxylation is consist ent with the extent of carboxylate formation in tin(IV) isopropoxide/v aleric acid solutions. Hydrogen peroxide treatment of tin valerate fil ms removes organic ligands and increases the level of backbone oxygen. Hydrogen peroxide treatment or calcination results in the formation o f amorphous tin(TV) oxide films.