Cuprous oxide (Cu2O) was grown on SrTiO3 (STO)(100) by oxygen plasma assisted molecular beam epitaxy. Microstructure of the grown layer and Cu valence state were analyzed using x-ray diffraction (XRD), x-ray photo-electron spectroscopy (XPS), atomic force microscopy (AFM), and cross-sectional transmission electron microscopy (TEM) as well as electron diffractions. The grown layer was dominated by Cu2O phase, possessing an epitaxial orientation with the substrate such that: Cu2O[001]//STO[001] and Cu2O(100)//STO(100). Cu2O film morphologically shows dependence on the growth rate. Typically, a fast growth will lead to the formation of a thin film with a relatively smooth surface. A slow growth will lead to the development of nanoparticles, featuring the formation of Cu2O pyramid. The pyramids are invariantly defined by the Cu2O {111} planes. Given the fact that the {111} planes correspond to the lowest surface energy of Cu2O, a slow growth will lend the system enough time to allow it to adopt the pyramid configuration by which the overall energy of the system was minimized.
Revised: April 7, 2011 |
Published: February 7, 2007
Citation
Yu Z., C.M. Wang, M.H. Engelhard, P. Nachimuthu, D.E. McCready, I. Lyubinetsky, and S. Thevuthasan. 2007.Epitaxial Growth and Microstructure of Cu2O Nanoparticle/thin Films on SrTiO3(100).Nanotechnology 18.PNNL-SA-53321.doi:10.1088/0957-4484/18/11/115601