Effect of ytterbium doping on the optical and electrical properties of intrinsic In2O3 thin films

Ytterbium doped In2O3 thin films (0.5%, 1.0%, 1.4%, 1.7% and 8.5 wt.%) have been prepared by a vacuum evaporation method on glass and silicon-wafer substrates. The prepared films were characterised by X-ray fluorescence, X-ray diffraction, UV-VIS-NIR absorption spectroscopy, and electrical (ac and dc) measurements. Experimental data indicate that Yb3+ doping slightly stress the In2O3 crystalline structure and change the optical and electrical properties. The electrical and optical behaviours of the Yb-doped In2O3 films show that they are wide-band semiconductors with band gap 3.67-3.7 eV and insulating properties. The ac and dc-electrical measurements show that it is possible to use Yb-doped In2O3 as an optical-sensitive high-k insulator for metal-insulator-silicon configurations. (C) 2009 Elsevier Ltd. All rights reserved.