Title

Impact of oxygen source parameters on homoepitaxial ZnO films grown at low-temperature on Zn-polar substrates

Authors

Authors

M. Wei; R. C. Boutwell; G. A. Garrett; K. Goodman; P. Rotella; M. Wraback;W. V. Schoenfeld

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

J. Alloy. Compd.

Keywords

ZnO; Molecular beam epitaxy; Homoepitaxy; Oxygen plasma; Atomic force; microscopy; MOLECULAR-BEAM EPITAXY; PLASMA; CRYSTAL; Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy &; Metallurgical Engineering

Abstract

ZnO thin films were epitaxially grown on Zn-polar (0001) ZnO substrates by plasma-assisted molecular beam epitaxy at a low temperature of 610 degrees C. The influence of Zn/O ratio on the epitaxial growth of ZnO was investigated. By optimizing the Zn/O ratio, a surface root mean square roughness of 0.277 nm with one or two monolayer height steps was achieved at a low growth temperature by growing on ZnO substrates with 0.5 degrees miscut angle toward the [1 (1) over bar 00] axis. Electrostatic ion trapping of the oxygen plasma was found crucial to deflect etching oxygen species at an oxygen flow rate of two standard cubic centimeters per minute, resulting in fewer surface defects and a longer photoluminescence (PL) lifetime of 217 ps. The impact of oxygen source gas purity was studied by high resolution X-ray diffraction and time-resolved photoluminescence (TRPL) measurements of resultant epilayers and higher gas purity was found necessary to reduce non-radiative centers. (C) 2012 Elsevier B. V. All rights reserved.

Journal Title

Journal of Alloys and Compounds

Volume

552

Publication Date

1-1-2013

Document Type

Article

Language

English

First Page

127

Last Page

130

WOS Identifier

WOS:000313653300022

ISSN

0925-8388

Share

COinS