Abstract
Starch capped ZnO/ZnS core/shell nanostructures are synthesised by a simple chemical bath deposition (CBD) method at room temperature. In this report, synthesis of ZnO nano tripod structures coated with ZnS shell and their optical properties are presented. Structural characterization is done by X-Ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). XRD of the core / shell film shows the presence of diffraction peaks both for ZnO and ZnS. In this work, we have been capable to find the rare hexagonal phase in addition to the cubic phase of ZnS. HRTEM images of ZnO/ZnS nanostructures reveal very vividly the formation of core-shell quantum dots. UV-Vis spectrum exhibits the absorption edge of ZnO/ZnS nanoparticles at about 400nm. With respect to core, core-shell system significantly improved the fluorescence quantum yield but the shell growth is accompanied by a small red shift (5–5.5 nm) of the Excitonic peak in the photo-luminescence (PL) wavelength, suggesting a partial leakage of the exciton into the shell material. Thus, enhanced fluorescence quantum yield due to core/shell nanostructures will bring in possibilities for a wide range of application fields..
Keywords
ZnO/ZnS core/shell, Fluorescence Quantum Yield, Red shift, ZnO nano tripod.
Citation
SUJATA DEB, P. K. KALITA, P. DATTA, Synthesis and optical properties of starch capped ZnO/ ZnS core/shell nanocomposites through chemical bath deposition method, Optoelectronics and Advanced Materials - Rapid Communications, 7, 9-10, September-October 2013, pp.648-653 (2013).
Submitted at: Feb. 12, 2013
Accepted at: Sept. 18, 2013