Sb doping behavior and its effect on crystal structure, conductivity and photoluminescence of ZnO film in depositing and annealing processes

Abstract The Sb-doped ZnO (ZnO:Sb) and undoped ZnO films with wurtzite structure and (0 0 2) preferred orientation were deposited on Si(1 0 0) substrate at 550 °C. It is deduced from XRD and XPS measurements that the Sb in the as-grown ZnO:Sb has high oxidation state and dopes in the form of oxygen-rich Sb–O clusters, which results in a large inner stress and a great increase of the c -axis lattice constant. After annealing at 750 °C under vacuum, the c -axis lattice constant of the ZnO:Sb decreases sharply to near the value of ZnO bulk, the electrical properties change from n-type to p-type and the PL intensity ratio of the visible to ultraviolet emission band goes down greatly, as the Sb content increases from 0 to 2.1 at.%. EDS and XRD measurements indicate that some of Sb dopants escape from the ZnO:Sb films and the oxygen-rich Sb-O clusters vanished after the annealing process. The effect of the change in Sb doping behavior on crystal structure, conductivity and PL is discussed in detail.