Structural and optical properties of epitaxial Cu$_{\mathbf{2}}$O ZnO superlattices
POSTER
Abstract
Superlattices with alternating layers of Cu$_{2}$O and ZnO have been prepared by magnetron sputtering on -sapphire (Al$_{2}$O$_{3})$ substrates at 650°C. The thickness, density, and roughness of obtained samples were analyzed by X-ray reflectivity (XRR) assisted with meticulous analytical data fittings, while X-ray diffraction (XRD), Grazing Incidence X-ray Diffraction (GIXRD), and phi scans were employed to verify their epitaxial qualities. For the superlattices starting with Cu$_{2}$O, the epitaxy was superior to those starting with ZnO as judged by transmission electron microscopy (TEM) atomic imaging and associated electron diffraction. The electronic band structures based on the first-principles calculations will be illustrated in comparison with the optical transitions inferred from photoluminescence spectroscopy.