Metal Insulator Transition in Ga doped ZnO thin films

Gallium (Ga) doped Zinc Oxide (ZnO) thin films are grown at room temperature (300 K) by reactive pulsed DC magnetron sputtering technique using 2 wt% and 4 wt% Ga doped ZnO targets. The temperature dependent resistivity studies have shown a semiconducting behavior with negative temperature coefficient of resistance for 2wt % Ga doped samples. A metal insulator transition (MIT) is observed for 4 wt % Ga doped targets, the possible reason for MIT may be attributed to the dopant disorder based localization for charge carriers at low temperatures.