Effect of Annealing Temperature in ZnO for Photonic Applications

Abstract

ZnO nanorods were synthesized on glass substrate by two step chemical bath deposition (CBD) method and annealed at different temperatures in argon environment for 1 hour. The structural and optical properties of the as-grown and annealed samples were investigated using X-ray diffractometer (XRD), UV-Visible-NIR spectroscopy, Raman spectroscopy and photoluminescence (PL) measurement. As grown sample has the largest crystallite size with a photonic gap of 90 nm whilst. Raman measurement shows sharp E2 (H) peak typical for the wurtzite ZnO structure and PL spectra exhibit a strong UV emission peak at 380 nm for all samples. The ratio of UV to visible peak in the PL spectrum for as grown sample was the highest indicating lowest level of defects for these set of samples. This is consistent with the crystallinity of the samples. Results suggest potential of using CBD as a method of growth for synthesizing ZnO nanorods for nanophotonic devices.