Growth of optically active multilayer metal oxide films on a plastic substrate

An optically active ITO/Au/ITO multilayer coating (where ITO stands for an indium tin oxide with the composition 90% In2O3 + 10% SnO2 and Au is nanoparticulate gold on a thin-film poly(ethylene terephthalate) substrate) has been prepared by a solution-phase process using an ITO nanopowder dispersion in isopropanol and a solution of chloroauric acid, which was converted to colloidal gold by photolysis. A sol–gel process has been proposed for the synthesis of tin-doped indium oxide nanopowder. The properties and composition of the powder were assessed by IR spectroscopy, thermal analysis, electron microscopy, and X-ray diffraction. The phase composition of the ITO nanopowder and the optical properties of the films grown using the nanopowder have been shown to depend on the thermal annealing conditions during synthesis. Layer-by-layer growth of metal oxide films in ITO/Au/ITO coatings influences the absorption in the composite in the IR spectral region.