Abstract
Highly c-axis oriented zinc oxide (ZnO) thin films with a wurtzite structure have been grown on glass substrates by metal organic chemical vapor deposition. The influence of growth parameters on the luminescent properties of the ZnO layers is investigated. It is shown that the growth temperature and VI/II ratio strongly influence the luminescent properties of ZnO thin films. For the films grown at low temperatures (250–325°C) a broad violet emission band at about 3.1eV has been observed. As the growth temperature increases, ultraviolet emission dominates the spectra and deep level emission is suppressed. It is suggested that the violet emission depends on grain size and hence the width of the free-carrier depletion region at the particle surface; the narrower the depletion width compared to the grain size, the higher the intensity. The result suggests that the mechanism responsible for the violet emission is recombination of delocalized electrons close to the conduction band with holes trapped in neutral zinc vacancy (VZn0) centers. For films grown under different VI/II ratios, the spectra are increasingly dominated by deep level emission as the VI/II ratio is increased. This broad emission is resolved into three bands at ∼2.0, ∼2.3, and ∼2.5eV. Based on the growth conditions, possible origins are proposed and discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
