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

[Display omitted] •MgZnO:F films with high Mg content were synthesized by RF magnetron co-sputtering.•Structural, electrical and optical properties of the films were investigated.•F occupied O sites, decreased the resistivity without reducing optical loss.•Low resistivity and high carrier concentration were simultaneously realized. 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 × 10-1 Ω⋅cm), high Hall mobility (3.55 cm2/Vs) and high carrier concentration (1.39 × 1019 cm−3) were simultaneously realized in the annealed MZO:F film. The effects of doping concentration 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.