Preparation And Properties Of Transparent Conductive Film Based On In₂O₃

Doped indium oxide transparent conductive films have been widely used in various optoelectronic devices, because of their unique optical and electrical properties such as high transmittance in the visible region, high reflectance in the IR region and low resistivity. It is, therefore, very important and useful to study the preparation and properties of the transparent conductive films. This dissertation is focused on the preparation, post-deposited annealing treatment and determination of optical constants of the transparent conductive films. The main contents are arranged as follows,Firstly, the optical constants and thickness of Nb₂O₅ optical films and ITO transparent conductive films have been retrieved by simulating normal incidence transmittance in the visible region. As a result, the simulated transmittance is consistent with the measured transmittance, and the optically optimized thickness agrees with the truth. Especially, we can also determine the optical constants of thin film with less interference in transmittance spectra by this method.Secondly, a new dielectric model which combines the Forouhi-Bloomer model and modified Drude model has been proposed. Based on this model, the optical constants and thickness of ITO films have been retrieved by simulating normal incidence transmittance, and the electrical parameters are obtained from the optical simulation. The simulated transmittance spectra fit excellently the measured spectra. The optically optimized thickness and optical constants accord with the measurement data, and the electrical parameters obtained electrically and optically are confirm with each other.Thirdly, ITO films are deposited by direct current magnetron sputtering and annealed in N₂. The structure, morphology, optical and electrical properties of the films are investigated. The results show that the as-deposited film has high transmittance (＞90%) in the visible region and low resistivity of～10^-3Ωcm. When ITO films are annealed at higher temperatures, the crystallinity is apparently improved, and the resistivity decrease drastically, while the high quality of transmittance within the visible region is maintained.Finally, titanium doped indium oxide (ITiO) transparent conductive films are prepared by direct current magnetron sputtering with different sputter pressure and power. Influence of the sputter pressure and power on the optical and electrical properties of ITiO films is investigated. It is found that ITiO films deposited with higher pressure and power have better optical and electrical properties.