کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5439240 | 1398192 | 2017 | 18 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The influence of Pb-doping on the crystal structure and luminescence properties of LiEuMo2O8 red-emitting phosphors
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
High efficiency red phosphors, showing spectral range of 610-620Â nm and a narrow-line emission, are helpful for achieving high color rendering index (CRI) and low correlated color temperature (CCT) phosphor-converted white-light diodes. Red phosphors activated by trivalent europium (Eu3+) thus have attracted a renewed interest for pc-WLEDs. In our case, we prepare a series of Pb2+-doped LiEuMoO8 red-emitting phosphors by solid-state reactions. The introduction of Pb2+ ions expands and distorts slightly the unit cell volume of LiEuMo2O8 matrix, and red-shifts the charge transfer absorption (CTA) band of LiEuMo2O8, which are demonstrated by X-ray powder diffraction, absorption spectra and micro-Raman spectra. Photoluminescence and photoluminescence excitation spectra results show that the excitation efficiency of Eu3+ is improved significantly in the near ultraviolet region when Pb2+ ions are doped into the host lattice. At x=0.015, the red-emitting intensity of LiEuMo2O8 is enhanced by 50%, and the internal quantum yields is 53% under excitation at 395Â nm. The enhanced red emission is discussed in term of the relaxation of parity-forbidden selection rules for trivalent europium luminescent center, and the sensitization effect of Pb2+ as a sensitizer for Eu3+ ions is negligible in LiEuMo2O8 under near ultraviolet excitation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 43, Issue 1, Part B, January 2017, Pages 1565-1570
Journal: Ceramics International - Volume 43, Issue 1, Part B, January 2017, Pages 1565-1570
نویسندگان
Pengpeng Dai,