کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5400463 | 1505917 | 2013 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Down-converted luminescence and energy transfer of α-KGd1âxEuxF4 nanophosphors with selective excitation
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A series of KGd1âxEuxF4 (x=1, 5, 10, 15, 20, 40, 60, 80 and 100Â mol%) nanophosphors were prepared by a simple and reproducible hydrothermal route. The structural and morphological properties of the samples were studied by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM), showing uniform nano-sized particles with cubic phase. The excitation spectra disclosed the intrinsic absorption bands of Eu3+5L6 state at 393Â nm and of Gd3+6IJ state at 272.4Â nm. From the downconversion (DC) emission spectra, it was found that the optimal Eu3+ concentration was 20Â mol% and 15Â mol% under 393Â nm and 272.4Â nm excitation, respectively. The nonradiative energy transfer (ET) mechanism is discussed and it turns out that ET of Eu3+-Eu3+ couple and Gd3+-Eu3+ couple occurs mainly via electric dipole-dipole and electric dipole-quadrupole interactions, respectively. From luminescence decay curves, the lifetimes of KGd1âxEuxF4 nanophosphors are seen to decrease with the increase of Eu3+ concentration. Both the emission spectra and luminescence decay curves show that downconversion ET between Gd3+ and Eu3+ ions is more efficient than that between Eu3+ and Eu3+ ions, thus suggesting potential applications in mercury-free fluorescence lamp and plasma display panel under vacuum ultraviolet (VUV) radiation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 143, November 2013, Pages 298-303
Journal: Journal of Luminescence - Volume 143, November 2013, Pages 298-303
نویسندگان
D.K. Xu, S.H. Yang, Y.L. Zhang,