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Research on Preparation and Spectrum Tuning of A3MgSi2O8: Eu2+, Mn2+ （A=Ca, Sr, Ba） Phsophors for Near-UV LED

Author: MaLiang
Tutor: WangDaJian
School: Tianjin University of Technology
Course: Condensed Matter Physics
Keywords: High temperature solid phase Spray pyrolysis Mesophase Flux Lumen enhancement effect Crystallinity Function of solid-state light source
CLC: TN312.8
Type: Master's thesis
Year: 2008
Downloads: 253
Quote: 0
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Abstract


The thesis discusses the near ultraviolet LED with a phosphor A 3 the MgSi 2 O 8 (A = Ca, Sr, Ba): Eu < sup> 2 , Mn 2 Preparation, crystal microstructure, the spectral characteristics and its high color rendering index WLED solid state light source and plant growth. Specifically, the paper has the following four aspects of innovation: 1. Discover and demonstrate a single matrix full spectrum phosphor the the Ba 3 the MgSi 2 O 8 : the of Eu 2 , Mn, 2 505nm green peaks derived from the intermediate phase Ba 2 SiO 4 : Eu 2 of the intrinsic emission. The ba 2 the SiO 4 generation owned by thermodynamic equilibrium chemical reactions under high-temperature calcination trend. Effectively suppressed by the flux added NH 4 Cl Ba 2 SiO 4 mesophase generation, and improve the target phase Ba 3 MgSi 2 O 8 , the degree of crystallinity. Conclusion is extended to the Ba 3 MgSi, 2 O 8 : the of Eu 2 and A 3 MgSi-2O 8 : Eu 2 , Mn 2 (A = Sr, Ca). Found prepared by spray pyrolysis the Ba 3 MgSi 2 O 8 : the of Eu 2 , Mn < sup> 2 samples the lumens enhancement effect. Changing the spray-drying temperature has no effect on the size of the phosphor particles, but then the light emission intensity influential. Spray pyrolysis lumens enhancement effect was attributed to the degree of crystallinity increased, The sample good UV absorption properties and light export efficiency. T. Aitasalo given Ba 3 the MgSi 2 O 8 : the of Eu 2 , Mn < sup> 2 crystal structure model based on Van Uitert empirical formula has been Eu 2 2 Sites of the electronic transition energies in different Ba its The results with the results and the experimental data points peak. However, Merwinite structure turned out to not apply to Ba 3 MgSi 2 O 8 . In addition, Mn 2 in which Sites of proved Ba 2 Sites of, and more likely to BaII the Sites of being replaced. . BaxSryCazMgSi 2 O 8 : the of Eu 2 , Mn 2 (xyz = 3) in two the aspects of the application of the function of solid state light sources: one is the growth of a plant function solid state light source; another solid state light of high color rendering index of white light function. Resonance energy transfer is widespread in BaxSryCazMgSi 2 O 8 : the of Eu 2 , Mn 2 (xyz = 3) in. To MgSi of Ba 3 2 O 8 : 0.02Eu 2 , xMn 2 is cases investigated Mn 2 doping amount of change in the energy transfer between the emission spectrum and Eu 2 and of Mn 2 . The role of energy transfer type dipole - dipole interaction. Demonstrated Ba 3 MgSi 2 O 8 : 0.02Eu 2 , 0.2Mn 2 and Ba 0.8 Sr 1.2 Si O 4:0.02 Eu 2 powder mixed to achieve high color rendering index white feasibility.

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CLC: > Industrial Technology > Radio electronics, telecommunications technology > Semiconductor technology > Semiconductor diode > Diodes: structure and performance > Light-emitting diodes
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