Facile Fabrication and Properties of Gd₂O₃:Eu³⁺, Y₂O₃:Eu³⁺ Nanophosphors and Gd₂O₃:Eu³⁺/Silica, Y₂O₃:Eu³⁺/Silica Nanocomposites

Abstract

Gd₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺ nanophosphors have been successfully fabricated by a combustion method at low temperature (350°C) in a short time (5 min) using natriethylenediaminetetraacetic acid (EDTA-Na₂) as fuel. The structure, morphology and size of Gd₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺ nanophosphors have been determined by x-ray diffraction and field emission scanning electron microscopy. Photoluminescence spectra indicated that the optimum Eu³⁺ ion concentrations with the strongest luminescence emission intensities are 5 mol.% for Y₂O₃:Eu³⁺ and 7 mol.% for Gd₂O₃:Eu³⁺. The nanocomposites of Gd₂O₃:Eu³⁺/silica and Y₂O₃:Eu³⁺/silica were fabricated by a sol–gel process with tetraethoxysilane (TEOS) as matrix material, and the nanocomposite compositions were analyzed by energy dispersion spectra. The strongest luminescence peaks from the ⁵D₀–⁷F₂ transition of the Eu³⁺ ion in Gd₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺ nanophosphors are between 613 nm and 615 nm. The Gd₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺ nanophosphors and their silica nanocomposites were studied to elucidate the influences of the Eu³⁺ concentration, host materials, annealing temperature, and weight ratio of TEOS and Gd₂O₃:Eu³⁺ or Y₂O₃:Eu³⁺.