Synthesis and luminescence properties of ZnGa₂O₄ spinel doped with Co²⁺ and Eu³⁺ ions

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• 作者：Xiulan Duan ; ^{xlduan@sdu.edu.cn} ; Fapeng Yu ; Yuanchun Wu
• 关键词：ZnGa2O4 ; Co ; Eu ; Citrate sol&ndash ; gel method ; Nanopowders ; Luminescence
• 刊名：Applied Surface Science
• 出版年：2012
• 出版时间：15 November, 2012
• 年：2012
• 卷：261
• 期：Complete
• 页码：830-834
• 全文大小：380 K

文摘

ZnGa₂O₄ nanopowders doped with Co²⁺ and Eu³⁺ ions, including dual doping, have been synthesized by citrate sol-gel method, and characterized by X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Results show that ZnGa₂O₄ spinels were produced by calcining the gel above 500 ¡ãC, with the crystallite size of 16-30 nm in the temperature range of 500-900 ¡ãC. Co²⁺ ions are located at the tetrahedral sites of ZnGa₂O₄ spinel by replacing Zn²⁺, and Eu³⁺ ions are incorporated in the defect regions at the grain boundaries. The emission spectra of Eu-doped ZnGa₂O₄ nanopowders display an intense emission at 615 nm belonging to ⁵D₀-⁷F₂ transition of Eu³⁺ ions. With the introduction of Co into Eu-doped ZnGa₂O₄, the emission intensity at 615 nm decreases, while the luminescence at 680 nm due to tetrahedral Co²⁺ increases. The result indicates that the energy transfer occurred from Eu³⁺ to Co²⁺ ions. The energy transfer was also studied by the luminescence decay behavior. The emission of Co and Eu Co-doped ZnGa₂O₄ also changed with annealing temperature. The luminescence properties of the doped ZnGa₂O₄ nanopowders can be controlled by the variation of Co and Eu doping concentration and annealing temperature.