Synthesis and characterization of F-doped MgZnO films prepared by RF magnetron co-sputtering

Fluorine-doped Mg0.21Zn0.79O (MZO:F) thin films were successfully deposited on glass substrates at room temperature by radio frequency (RF) magnetron co-sputtering method with Mg0.21Zn0.79O, MgF2, and ZnF2 targets. Low resistivity (1.26 x 10(-1) Omega.cm), high Hall mobility (3.55 cm(2)/Vs) and high carrier concentration 1.39 X 10(-19) cm(-3)) were simultaneously realized in the annealed MZO:F film. The effects of doping con- centration and annealing temperature on the structural, morphological, electronic, electrical and optical properties of MZO:F films were systematically investigated in this study. XRD and XPS analysis confirmed that F atoms have entered into crystal lattices of MZO and acted as donors when they occupied O sites in the hexagonal lattice. Moreover, it was observed that both doping concentration and annealing temperature greatly affected the crystallinity, grain size, growth orientation and surface morphology of the MZO:F thin films. In addition, the optical gap changed dramatically with the F content and annealing temperature, which could be attribute to the Burstein-Moss effect accompanied by the effects of fluctuating potential arising from the randomly situated impurities.