Judd–Ofelt analysis of luminescence emission from Zn 2SiO 4:Eu 3+ nanoparticles obtained by a polymer-assisted sol–gel method

Abstract

In this research we prepared Zn 2SiO 4:Eu 3+ phosphor nanopowders using a combination of sol–gel and combustion synthesis with the aim to examine the influence of synthesis conditions on the optical properties of the phosphor. As combustion fuels we used polyethylene glycol (PEG) with different average molecular weights, and the combustion was performed in two ways—in a microwave oven and a conventional furnace. Optical properties were examined by photoluminescence spectroscopy and spectra of all samples showed intense red emission, typical for f–f electronic transitions of the Eu 3+ ions. Emission decays exhibited classical one exponential behavior at longer times and nonlinear nature at short times, with average lifetimes varied from 0.49 to 0.71 ms between samples. Judd–Ofelt theory was applied to experimental data for the quantitative determination of optical parameters such as Ω 2,4 Judd–Ofelt parameters, radiative and nonradiative transition rates and emission quantum efficiency. Calculated parameters vary moderately between samples prepared with different PEGs and combusted in different manner.