Photoluminescent characterization of KNbO₃:Eu³⁺

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• 作者：Te-Hua Fang ; Yu-Jen Hsiao ; Yee-Shin Chang and Yen-Hwei Chang
• 关键词：Scanning electron microscopy ; X-ray diffraction ; Optical materials ; Optical emissitivity ; Photoluminescence
• 刊名：Materials Chemistry and Physics
• 出版年：2006
• 出版时间：10 December 2006
• 年：2006
• 卷：100
• 期：2-3
• 页码：418-422
• 全文大小：755 K

文摘

In this study, the photoluminescence (PL) spectra of europium-doped potassium niobate (KNbO₃) crystallites prepared by a vibrating milled solid-state reaction method were studied. X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical spectral analysis (luminescence excitation, emission spectra and time-resolved spectra) were used to characterize the KNbO₃:Eu³⁺ powders. The results of the XRD revealed that the powders remained as a single orthorhombic structure at doping concentrations below 3 mol % . A second phase of EuNbO₄ begins to appear at 5 mol % . The ⁵D₀–⁷F₁ (593 nm) and ⁵D₀–⁷F₂ (614 nm) emission characteristics of Eu³⁺ appear at a quenching concentration of above 3 mol % . The Commission Internationale d’Eclairage (CIE) chromaticity coordinates of a Eu:KNbO₃ host excited at λ_ex = 400 nm and λ_ex = 466 nm wavelengths, both presented a red-shift when increasing the Eu³⁺ ion doping. The lifetime of the Eu³⁺ ion decreased as the doping concentration was increased from 1 to 7 mol % .