ABSTRACT
This chapter summarizes some researches on optical properties of MgZnO/Zinc oxide (ZnO) heterostructures grown on sapphire substrates by Plasma-Assisted Molecular Beam Epitaxy. Besides the fabrication of wurtzite phase ZnMgO alloy films, ZnO/MgZnO quantum well structures for optoelectric applications in UV region also receive considerable attention. A number of researches are concerning the excitonic properties of ZnO/MgZnO quantum well structures. Although MgZnO/ZnO quantum wells and supperlattice structures have been frequently reported, there has been little information on the conduction and valence band offsets between ZnO and ZnMgO. Energy dispersive spectroscopy was used to determine the Mg contents in the MgZnO barrier. The composition of MgZnO thin films was controlled by adjusting the oxygen flow rate. In the early works, ZnO/MgZnO quantum well structures were firstly fabricated on Al2O3 substrates by metal-organic chemical vapor deposition and PMBE. M. Brandt et al. studied the properties of ZnO/MgZnO single heterostructures and MgZnO/ZnO quantum wells grown by pulsed-laser deposition on sapphire and ZnO.
