Regulate the content of magnesium in MgxZn1−xO films by vacuum anneal

MgxZn1−xO thin films were grown on c-sapphire substrates by metal-organic chemical vapor deposition (MOCVD), followed by annealing in vacuum at different temperatures for 1 h. The UV emission peak was blue shifted in the photoluminescence (PL) spectra and a dramatic shift of (0 0 2) diffraction peak to higher angle was observed in X-ray diffraction (XRD) pattern with increasing anneal temperature. This suggested the band gap and the lattice parameter of MgxZn1−xO had been affected by annealing in vacuum. Furthermore, the structure of the film became sparser due to annealing in vacuum. From the X-ray photoelectron spectroscopy (XPS) and ICP of the MgxZn1−xO film, we can find that the anneal temperature have an effect on the content of each element in MgxZn1−xO quantitatively. In addition, the value of x in MgxZn1−xO varied slightly as the annealing temperature increased. The above phenomena indicated that annealing in vacuum could slightly adjust the percentage of Mg indirectly in MgxZn1−xO film and offer a good idea in MgxZn1−xO devices facture.