Preparation And Performance Optimization Of ZnO Transparent Conductive Films

Transparent conductive films are functional film material widely used in photoelectronic devices such as liquid crystal display, solar cell, and energy-saving glass, etc. Among this kind of materials within the category, ZnO shows high visible transmittance combined great conductivity and is a promising alternative to ITO due to its abundance in nature, low cost, relatively low deposition temperature, and stability in hydrogen plasma.F-doped ZnO (FZO) transparent conductive thin films were grown by RF magnetron sputtering at different temperature in our work. The influence of deposition pressure and temperature on the film properties is studied. In order to achieve better electrical property, FZO/Ag/FZO multilayer thin films were prepared with both use of RF and DC magnetron sputtering, and the effect of Ag layer thickness on the multilayer film properties was investigated. The main results are obtained as follow:1. FZO thin films were prepared on glass substrates by RF magmetron sputtering from a FZO ceramic target at room temperature. It’s critical to optimize the deposition temperature while other key factors such as F content (3at.%), deposition pressure (0.7Pa), power(100W) are fixed. FZO thin films grown at 350℃have the best properties and the lowest resistivity is 6.24×10-2Ωcm. The best mobility and highest carrier concentration is 1.64cm2/Vs and 8.96×1019cm-3 separately. The optimized figure of merit (φTC) of 1.68×10-4Ω-1 is obtained with the visible transmittance above 90%.2. FZO/Ag/FZO transparent conductive thin films were prepared on the glass substrate at room temperatue. The influence of Ag thickness was mainly studied. The Ag thickness shows great influence on the morphology and photoelectrical properties. The most optimized multilayer thin film is prepared with the Ag layer thickness at 8nm. The average visible transmittance is 90% and the figure of merit is 7.41×10-2Ω-1.3. FZO/Ag/FZO multilayer thin films were prepared on the PC flexible substrates at room temperature, which was compared with FZO/Ag and Ag/FZO bi-layers in properties. The effect of Ag layer deposition time is mainly investigated which turns out playing an important role in the photoelectrical perfoermance.