EFFECT OF POST-SYNTHESIS HEAT TREATMENT OF ZnO NANOPARTICLES IN DMF ON THEIR SIZE AND SPECTRAL AND LUMINESCENT PROPERTIES

摘要

A method is proposed for the formation of ZnO nanoparticles (NP) in dimethylformamide, which permits variation of the mean NP diameter from 3.6-3.7 to 6.0 nm by selecting the suitable duration and temperature of the post-synthesis heat treatment. The ZnO nanoparticles in DMF display characteristic photoluminescence, emitting in a broad band with maximum at 2.24-2.25 eV, with a quantum yield up to 13%, and a mean radiative lifetime of similar to 2 mu s. Giant enhancement of Raman scattering on the surface phonons of the ZnO NP is observed upon the photoexcitation of these NP with an island-like silver film deposited on their surface.