Magnetron-sputtered AZO thin films on commercial ITO glass for application of a very low resistance transparent electrode

In this paper, we report a coating method of reducing the sheet resistance of commercial Sn-doped In2O3 (ITO) glass by DC magnetron sputtering, without reducing its optical transmittance in the visible range of spectra. Aluminium oxide doped zinc oxide (AZO) films deposited on ITO glass showed highly (002)-oriented textured structure. An experimental procedure was designed to minimize the sheet resistance of AZO/ITO films in the deposition parameter space (mainly deposition temperature). Resistivity measurements showed that the ITO films with AZO coated under optimized deposition conditions showed a significant 81.4% decrease of sheet resistance when compared with those formed without AZO. Room temperature Hall effect measurements showed that the Hall mobility of the combined layers was greatly increased compared with that for single layer ITO. A high quality transparent electrode, having a resistance as low as 4.13 Omega/square and a high optical transmittance of 80% in the visible spectral range (with substrate), was obtained. The bilayer AZO/ITO film glass may be a good alternative substrate to ITO glass for advanced electro-optic applications.