Full Length ArticleOptical investigations of ZnO/ZnMgO quantum wells in self-assembled ZnMgO nanocolumns grown on Si (111) by MBE

Epitaxial growth of semiconductor nanocolumns has attracted large interest in recent years as means to fabricate nano-sized devices. Nanostructures grown on Si (111) substrates are very useful for applications in optoelectronics and integrated optoelectronic circuits. We present the catalyst-free ZnMgO nanocolumns growth under high temperature conditions with asymmetric ZnO double quantum wells separated by ZnMgO barriers of different thickness (3 nm and 100 nm) deposited on Si (111) substrate using a molecular beam epitaxy method. The high quality quantum structures based on ZnMgO nanocolumns were characterized using scanning electron microscopy and optical spectroscopy (photo- and cathodoluminescence). Their luminescent characteristics were investigated using different techniques. Study of excitons in ZnMgO/ZnO/ZnMgO quantum wells is thus important to understand the optical properties of these semiconductor structures.