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Indexed by:期刊论文

Date of Publication:2012-09-01

Journal:APPLIED SURFACE SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:258

Issue:22

Page Number:8673-8677

ISSN No.: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.