core/shell nanocrystals, size series, zno, cdse, nanoparticles, photoluminescence, energy, layer, wells, Science & Technology, Physical Sciences, Technology, Chemistry, Multidisciplinary, Crystallography, Materials Science, Multidisciplinary, Chemistry, Materials Science, CORE/SHELL NANOCRYSTALS, SIZE SERIES, ZNO, CDSE, NANOPARTICLES, PHOTOLUMINESCENCE, ENERGY, LAYER, WELLS, 0306 Physical Chemistry (incl. Structural), 0912 Materials Engineering, 0302 Inorganic Chemistry, Inorganic & Nuclear Chemistry
ZnO/MgO quasi core-shell quantum dots (QDs) were grown by a metal-organic chemical vapor deposition method on silicon substrates. The core-shell structure was well-characterized by a combination of cross-sectional transmission electron microscopy and angle-resolved X-ray photoelectron spectroscopy (XPS). Valence band XPS measurements were performed to investigate the effects of MgO shell layer on the energy band of ZnO/MgO QDs. Photoluminescence (PL) emission from the QDs showed remarkable enhancement after the growth of the MgO layer. In addition, exciton binding energy of 118 +/- 5 meV in the ZnO/MgO QDs was obtained from temperature-dependent PL.