کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5402648 | 1392739 | 2009 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Short-wavelength luminescence in Ho3+-doped KGd(WO4)2 crystals
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Emissions from the high-lying excited states, energy transfer and upconversion processes are investigated in Ho3+-activated KGd(WO4)2 crystal. The spectral assignment based on time-resolved emission spectra allowed to identify various near ultra-violet (UV), blue and green emissions starting from the excited 3H5, 5G4, 5G5, 5F3 and 5S2 levels. The temporal behavior of these transitions after pulsed excitation was analyzed as a function of temperature and holmium ions concentration. The shortening and nonexponentiality of the decays, observed with increasing activator concentrations, indicated cross-relaxation (CR) among the Ho3+ ions. Cross-relaxation rates were experimentally determined as a function of activator concentration and used to evaluate the values of the nearest-neighbor trapping rates X01 and to model the decays. It was observed that KGW, despite higher than in YAG maximum phonon energy of about 900Â cmâ1, is more efficient short-wavelength emitter than YAG. Examples of the excited-state absorption (ESA) and energy transfer (ET) mechanisms responsible for the upconverted, short-wavelength emissions were identified by analyzing fluorescence dynamics and possible energy resonances.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 129, Issue 12, December 2009, Pages 1505-1508
Journal: Journal of Luminescence - Volume 129, Issue 12, December 2009, Pages 1505-1508
نویسندگان
M. Malinowski, M. Kaczkan, S. StopiÅski, R. Piramidowicz, A. Majchrowski,