Transparent Conductive Oxide Nanocrystals: New Synthesis Route, Characterization and Applications.

摘要

Nanocomposites with dispersed inorganic nanoparticles offer functional properties not available in each individual component. For optically transparent nanocomposites, a high transmittance is required for practical applications. Thus, the nanoparticles must be uniformly dispersed in the polymer matrix with little agglomeration. In this thesis, it was achieved by a new synthesis route in which reaction induced organic encapsulated nanoparticles with high dispersibility are formed during the reaction.;Using this method, we have synthesized nearly monodisperse, various shaped In2O3 nanocrystals from indium stearate including deltoidal icositetrahedral indium oxide which was developed for the first time. The formation mechanism of various In2O3 morphologies under different conditions was also investigated in detail. In addition, nearly monodisperse ~7 nm indium tin oxide (ITO) nanocrystals without any agglomerations were efficiently synthesized by pyrolysis of the indium-tin stearate precursor without using any additional organic solvents. Both TOF-SIMS and TGA measurements reveal that the ITO nanocrystals exhibit a core-shell structure which has an ITO core and a stabilizer shell. The ITO nanocrystals could not only be dispersed homogeneously in non-polar solvents forming optically clear solutions but also distributed homogeneously in PVB matrix, resulting in transparent ITO/PVB nanocomposites which show over 80% transmittance in visible light range as well as efficient NIR absorption/reflection, and have been used as interlayer for fabricating laminated glass in solar control glazing. Furthermore, ~10 nm IZO nanocrystals were synthesized via excess alcohol-assisted pyrolysis and could also be dispersed in the nonpolar solvent forming optically clear solution. The hexane solution with 1 wt% IZO nanocrystals can block the 100% UV light and become an excellent UV absorber.