Optical probing of MgZnO/ZnO heterointerface confinement potential energy levels

Low-temperature photoluminescence and reflectance measurements were employed to study the optical transitions present in two-dimensional electron systems confined at MgxZn1-xO/ZnO hetero-junctions. Transitions involving A- and B-holes and electrons from the two lowest subbands formed within the confinement potential are detected. In the studied density range of 2.0-6.5 x 10(11) cm(-2), the inter-subband splitting is measured and the first excited electron subband is shown to be empty of electrons. (C) 2015 AIP Publishing LLC.