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The Luminescence Properties of GdMAl3O7:Re(M=Mg, Ca, Sr, Ba; Re=Eu3+, Eu2+, Tb3+)

Author: TangWei
Tutor: HeDaWei
School: Beijing Jiaotong University
Course: Materials Physics and Chemistry
Keywords: Aluminate Phosphor Energy transfer Rare earth ions White LED Green
CLC: O482.31
Type: Master's thesis
Year: 2009
Downloads: 9
Quote: 0
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Abstract


At present, various types of the phosphor development and research increasingly attention has been paid crystals doped with rare earth ions has become a focus for researchers. In this paper, high-temperature solid phase prepared by the rare earth ion doped GdMAl 3 O , 7 alkaline earth metal series phosphor and its structural characteristics and luminescent properties were studied. GdMAl 3 O 7 : the Reu 3 X-ray powder diffraction data with JCPDS (Ca :50-1808, Sr :50-1817) standard Cards found better, indicating that our synthetic material is an alkaline earth metal aluminate, and the incorporation of the rare-earth active ions did not cause obvious changes in the matrix structure. GdCaAl 3 O 7 : Eu 3 phosphor 200nm-300nm a broad excitation band due the of Eu 3 neighboring O 2 - generated by charge transfer occurs; five excitation peak at 300nm-500nm, corresponding to the of Eu 3 of 7 F 0 5 the D 4 5 G 2 5 L 6 , 5 D 3 , 5 D 2 of level transition, the strongest peaks at 393nm ( 7 F 0 → 5 L 6 ). 393nm excitation, showing Eu 3 5 D 0 → 7 F J The characteristic emission, GdCaAl 3 O 7 : Eu 3 615nm (Eu 3 electric dipole < sup> 5 D 0 → 7 F 2 ) emitted mainly, GdMgAl 3 O < sub> 7 : Eu 3 the 587nm (the of Eu 3 the magnetic dipole 5 D 0 → 7 F 1 ) mainly. 393nm excitation GdCaAl 3 O 7 : the of Eu 3 emission than GdMgAl 3 O 7 : the of Eu 3 , 253nm excitation, GdMgAl , 3 O 7 : the of Eu 3 absorption than GdCaAl 3 O 7 : the of Eu 3 , which is mainly due to both determines the strength of the absorption of light. GdMAl 3 O 7 : Eu 2 (M = Ca, Sr, Ba) series of samples has a strong absorption in the range of 250nm-400nm . 380nm long wave ultraviolet excitation, the emission peak rendered symmetrical distribution, Eu 2 of the 5d-4f transition characteristic emission, by the order of Ca, Sr, Ba, the emission peak move significantly toward the long wavelength emission peak are located at 440nm, 498 nm, 516nm, which most GdBaAl 3 O 7 : Eu 2 emission peaks at 516nm The half-peak width of about 50nm, the green phosphor can be applied to the white LED. GdSrAl 3 O 7 : Tb 3 in the ultraviolet region of the strong absorption of the excitation peak at 229nm, 243nm (the Tb 3 < / sup> 4f 8 → 4f 7 5d 1 transition) and 274nm (the Gd 3 8 S 7/2 → 6 I J transitions), suggesting that Gd 3 and Tb 3 occurred between the energy transfer. 243nm excitation the Tb 3 to 5 D 4 → 7 F 5 (547nm) green emission is strongest.

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CLC: > Mathematical sciences and chemical > Physics > Solid State Physics > Solid nature of the > Optical Properties > Luminescence
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