Single-Component and Warm-White-Emitting Phosphor NaGd(WO4)2:Tm3+, Dy3+, Eu3+: Synthesis, Luminescence, Energy Transfer, and Tunable Color

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• 作者：Yan Liu ; Guixia Liu ; Jinxian Wang ; Xiangting Dong ; Wensheng Yu
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：November 3, 2014
• 年：2014
• 卷：53
• 期：21
• 页码：11457-11466
• 全文大小：806K
• ISSN：1520-510X

文摘

Tm³⁺, Dy³⁺, and Eu³⁺ codoped NaGd(WO₄)₂ phosphors were prepared by a facile hydrothermal process; they were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectrometer (EDS), photoluminescence spectra, and fluorescence lifetime. The results show that the novel octahedral microcrystals with a mean side length of 2 渭m are obtained. Under the excitation of ultraviolet, individual RE³⁺ ion (Tm³⁺, Dy³⁺, and Eu³⁺) activated NaGd(WO₄)₂ phosphors exhibit excellent emission properties in their respective regions. Moreover, when codoping Dy³⁺ and Eu³⁺/Tm³⁺ in the single component, the energy migration from Dy³⁺ to Eu³⁺ has been demonstrated to be a resonant type via a dipole鈥搎uadrupole mechanism as well as that from Tm³⁺ to Dy³⁺ ions, of which the critical distance (R_Dy鈥揈u) is calculated to be 11.08 脜. More significantly, in the Tm³⁺, Dy³⁺, and Eu³⁺ tridoped NaGd(WO₄)₂ phosphors, the energy migration of Tm³⁺鈥揇y³⁺鈥揈u³⁺, utilized for sensitizing Eu³⁺ ions besides compensating the red component at low Eu³⁺ doping concentration, has been discussed first. In addition, under 365 nm near-ultraviolet radiation (nUV), the color-tunable emissions in octahedral NaGd(WO₄)₂ microcrystals are realized by giving abundant blue, green, white, yellow, and red emissions, especially warm white emission, and could be favorable candidates in full-color phosphors for nUV-LEDs.