Enhancement of UV photoluminescence in ZnO tubes grown by metal organic chemical vapour deposition (MOCVD)

• Main Authors: Iwan, S., Zhao, J. L., Tan, Swee Tiam, Sun, X. W.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; ZnO Tubes; MOCVD
• Online Access: https://hdl.handle.net/10356/141166
• Institution: Nanyang Technological University

We have synthesized ZnO tubes, without any catalyst, on Al2O3 (001) substrates by metal organic chemical vapor deposition (MOCVD) at different growth temperatures, pressures and Zn-O ratios. The results confirm that the growth temperature, reactor pressure and Zn-O ratio play important roles in the formation of hexagonal ZnO tubes. Scanning electron microscopy (SEM) images indicated that, at a growth temperature of 500 °C, reactor pressure of 75 Torr and Zn-O ratio of 10/75 are an appropriate condition to obtain hexagonal and well-aligned ZnO tubes. High-resolution, double crystal XRD analysis shows a symmetric ω-scan rocking curve, with a full width at half maximum (FWHM) of 1.1°. It confirms the ZnO tubes have highly c-axis orientation on Al2O3 substrate. Subsequently, room temperature photoluminescence (PL) studies confirm that the enhancement of UV emissions from ZnO tubes is due to increasing Zn-O ratios.