Far-infrared optical constants of ZnO and ZnO/Ag nanostructures

authors	Zamiri, R; Rebelo, A; Zamiri, G; Adnani, A; Kuashal, A; Belsley, MS; Ferreira, JMF
nationality	International
journal	RSC ADVANCES
keywords	ENHANCED RAMAN-SCATTERING; CORE-SHELL NANOCOMPOSITES; PHOTOCATALYTIC PROPERTIES; SILVER NANOPARTICLES; LASER-ABLATION; SEMICONDUCTOR; NANOCRYSTALS; FABRICATION; NANOWIRES; NANOTUBES
abstract	We report on the synthesis of ZnO nanoplates and ZnO nanoplate/Ag nanoparticle heterostructures via a simple and cost effective wet chemical precipitation method. The prepared samples were characterized for structural and optical properties by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV-VIS reflectance, Raman, and FT-IR spectroscopy. The Kramers-Kronig (K-K) method and classical dispersion theory was applied to calculate the far-infrared optical constants such as, refractive index n(omega), dielectric constant epsilon(omega), transverse optical phonon (TO) and longitudinal (LO) optical phonon modes. We determined various optical constant values n(omega) and epsilon(omega) for ZnO nanostructures in the range of 0 to 9 and 0 to 70, respectively. Whereas, for Ag deposition on ZnO nanostructures, the corresponding n(omega) and epsilon(omega) values were found to be increased in the range of 0 to 30 and 0 to 800, respectively. The TO and LO optical phonon modes of ZnO nanoplate/Ag nanoparticle heterostructures were also found to be higher (416 cm(-1), 620 cm(-1)) when compared with corresponding values obtained for ZnO nanoplates (415 cm(-1), 604 cm(-1)).
publisher	ROYAL SOC CHEMISTRY
issn	2046-2069
year published	2014
volume	4
issue	40
beginning page	20902
ending page	20908
digital object identifier (doi)	10.1039/c4ra01563k
web of science category	Chemistry, Multidisciplinary
subject category	Chemistry
unique article identifier	WOS:000336833400036