Magnesium incorporation efficiencies in MgxZn1−xO films on ZnO substrates grown by metalorganic chemical vapor deposition**Project supported by the National Natural Science Foundation of China (Grant No. 61474121) and the Major Scientific Project of Fujian Province, China (Grant No. 2014NZ0002-2).

Abstract

We investigate the magnesium (Mg) incorporation efficiencies in MgxZn1−xO films on c-plane Zn-face ZnO substrates by using metalorganic chemical vapor deposition (MOCVD) technique. In order to deposit high quality MgxZn1−xO films, atomically smooth epi-ready surfaces of the hydrothermal grown ZnO substrates are achieved by thermal annealing in O2 atmosphere and characterized by atomic force microscope (AFM). The AFM, scanning electron microscope (SEM), and x-ray diffraction (XRD) studies demonstrate that the MgxZn1−xO films each have flat surface and hexagonal wurtzite structure without phase segregation at up to Mg content of 34.4%. The effects of the growth parameters including substrate temperature, reactor pressure and VI/II ratio on Mg content in the films are investigated by XRD analysis based on Vegard’s law, and confirmed by photo-luminescence spectra and x-ray photoelectron spectroscopy as well. It is indicated that high substrate temperature, low reactor pressure, and high VI/II ratio are good for obtaining high Mg content.