Microwave pulse-assisted wet chemical synthesis of ZnO nanoparticles with excellent UV emission

Abstract

ZnO nanoparticles (ZNPs) were synthesized by wet chemical method using poly vinyl alcohol (PVA) templates. Uniform growth, high yield and excellent optical properties were observed in ZNPs synthesized under pulsed microwave irradiation (PMW). Moreover the dangling bonds of ZNPs prepared under PMW were passivated more effectively than in samples prepared without it. Strong UV emission peaks at ~ 360 nm and 380 nm, along with a feeble defect-related visible emission peak at ~ 465 nm, were observed in the room temperature (RT) photoluminescence (PL) spectra of ZNPs. Observation of two distinct excitonic peaks in RT UV-vis optical absorbance spectra and high UV-to-visible PL intensity ratio show high quality of ZNPs prepared by the present method. FTIR spectra were employed to explain the surface passivation mechanism of PVA.