Dependence of carrier concentrations on oxygen pressure for Ga-doped ZnO prepared by ion plating method

Abstract Transparent and conductive Ga-doped ZnO films have been deposited at a glass substrate temperature of 200 °C using an ion plating system. The resistivity as low as 2.7×10−4 Ω cm with a high carrier concentration of 8×1020 cm−3, Hall mobility of 27 cm2 (V s)−1 and high average transmittance above 90% in the visible range were obtained from the film deposited under reducing conditions using ZnO:Ga2O3 tablets with a Ga2O3 content of 3 wt.%. Under reducing conditions, carrier concentration decreases very slowly with increasing oxygen partial pressure. Excess oxygen partial pressure substantially decreases both carrier concentration and Hall mobility in the films.