Dependence of conduction type of ZnO films prepared by sputtering a Zn3As2/ZnO target on substrate temperature and thermal treatment

ZnO films were deposited on glass substrates by sputtering a Zn3As2/ZnO target using radio frequency (rf) magnetron sputtering. XRD was used to analyze the crystal orientation of ZnO films. Energy dispersive spectroscopy result shows that As content in ZnO:As films is nearly uniform. Room temperature Hall and resistivity measurements indicate that the substrate temperature is an important factor to determine conduction type of ZnO films and proper thermal treatment for the films may change their electrical behavior from n type to p-type. As-doped ZnO film shows p type conductivity with mobility as high as 4.07 cm2/V s after annealing in Ar ambient at 400 °C for 60 min.