Structural and optical properties of epitaxial In2O3/ZnO superlattices
POSTER
Abstract
Superlattices of shallow quantum well structures with alternating layers of In2O3 and ZnO have been prepared by sputtering at 923K on c-sapphire substrates. Optimization of the processing parameters was attempted through varying the sputtering power, deposition temperature, and number of periods. X-ray reflectivity (XRR) assisted with analytical data fittings was used to extract the thickness, density, and roughness of the samples, while X-ray diffraction (XRD), Grazing Incidence X-ray Diffraction (GIXRD), and phi scans were adopted to verify their epitaxy. The epitaxial qualities for the samples with In2O3 as a starting layer are superior to those starting with ZnO based on transmission electron microscopy (TEM) atomic imaging and electron diffraction. The electronic structures according to the first-principles calculations will be discussed in association with the optical properties inferred from optical transmission and photoluminescence spectroscopy.