A Study Of Preparation Of Nanoscaled Precursor Slurries And Coating Mechanics Of Indium Tin Oxide

Indium tin oxide (ITO) thin films are widely utilized as an essential part in many optoelectronic devices because of their unique properties of high electrical conductivity and high optical transparencies in the visible region.At present, ITO films are manufactured mostly by the magnetron sputtering, however, which should produce with the high cost value.The sol-gel method may be the most feasible way to prepare the low cost film. In this thesis, transparent conduction ITO films were fabricated on sode lime float glass substrate by the sol-gel method. The colloidal solutions were prepared from indium metal ingots and hydrous tin (VI) chloride and the ITO film was fabricated in the float glass by colloid dip-coating method. The stability of colloid was studied, and the electrical, optical and structural properties of ITO films were investigated.In this study indium and stannic chloride were used as raw material for obtaining ITO precursor slurries by adding some additives. The sedimentation experiment and viscosity measurement inferred that the ITO precursor solution has high stability when the pH of Indium Tin Oxide was8, the dosage of PEG was1.0-2.0wt%and the viscosity was2.1-2.6mPa:s (or the dosage of PVP was1.5-2.0wt%and the viscosity was2.0-2.3mPas) and the volume percent of solid particles in the solution was less than10%after sedimentated120h. Observed by the TEM and SEM image, the particle size of colloid ranged from10to30nm, and the dispersibility and stability of the ITO precursor slurries were good. In the view of zeta potential, the electrostatic effect and steric hindered effect between particles was studied in the colloid after adding surfactants.The dip-coating experiment showed that with the increase in the number of times of coating, the sheet resistance and the transmissivity of the ITO films was decreased when the raising speed was (6cm·min-1); with the raising speed increasing, the sheet resistance and the transmissivity of the ITO films was slowly decreased when the ITO film was deposited5layers.The results indicated that only cubic In2O3phase was observed in the ITO film, which was deposited51ayers, with deffrerent amount of doped Sn; with the amount of doped Sn increasing, the sheet resistance of ITO was up to minimum and then increased. The mean transmissivity of the ITO films was82.7%in400-800nm wavelength. The lowest sheet resistance value of ITO film, which was annealed at600℃for1h and was deposited51ayers, was153ohms per square.According to XRD, the ITO films annealed at300℃were the same as diffraction peak of indium tin oxide. The lowest sheet resistance value of ITO film was260Ω-1which was dried at150℃for quarter and annealed at600℃for60min at the heating-up speed of5℃·min-1.