Surface and Interface Characterization of Self-Assembled Copper Oxide Quantum Dots on SrTiO3(001) Surface
S. Thevuthasan, I. Lyubinetsky, A.S. Lea, D.R. Baer, C.F. Windish, C.M. Wang, M.H. Engelhard, V. Shutthanandan,,P. Nachimuthu, D.K. Shuh and Y.J. Kim
Pacific Northwest National laboratory, US
Keywords: oxide nano structures, XPS, XANES, oxygen plasma assisted MBE
Interface controlled nucleation and growth of two and three dimensional nano structures show unique structural, optical, electronic and vibrational properties due to the quantum confinement of charge carriers. When the size is sufficiently small, the three dimensional quantum dot structures show atom like discrete energy levels and several recent investigations were focused on tailoring these size effects in semiconductor technology, especially in electronic and optoelectronic applications. In general, the oxide quantum dots (OQD) have received much less attention and the growth and characterization of OQDs has been virtually unexplored. Recently we have successfully grown copper oxide QDs on SrTiO3(001) substrates using oxygen plasma assisted molecular beam epitaxy. Although the copper oxide QDs that were grown at low temperature (< 800 K) show mostly Cu2O phase, the QDs grown at higher temperatures appear to be consisting of Cu metal and Cu2O. In addition, a small amount of CuO was present in all the samples. Characterization of these materials has been a major challenge. Atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), x-ray absorption near edge spectroscopy (XANES) x-ray diffraction (XRD), Rutherford backscattering spectrometry and transmission electron microscopy (TEM) were used to characterize the surfaces and interfaces of these materials.
NSTI Nanotech 2003 Conference Technical Program Abstract