Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2012-09-01

Journal: APPLIED SURFACE SCIENCE

Included Journals: Scopus、EI、SCIE

Volume: 258

Issue: 22

Page Number: 8673-8677

ISSN: 0169-4332

Key Words: ZnO; Oxygen flow rate; Deep-level emission; Oxygen vacancy

Abstract: High-quality ZnO thin films were deposited on 6H-SiC substrates using metal-organic chemical vapor deposition system. The physical properties of as-prepared ZnO layers under various oxygen flow rate were thoroughly studied. An increase in the O/Zn ratio yielded a decrease in growth rate. The experimental results also indicated that the size of ZnO nanoparticles, lattice constant and compressive stress inside the films displayed a regular variety as a function of O-2-flow rate. In addition, with increase of oxygen discharge, the position of deep-level emission in photoluminescence spectra demonstrated a significant shift, with transformation from oxygen vacancy to zinc vacancy. The qualitative calculation from X-ray photoelectron spectroscopy data showed that higher O-2-flow rate was able to promote O-Zn bond formation and reduce the number of oxygen vacancies. (C) 2012 Elsevier B.V. All rights reserved.