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

The Quartet AgGd ( WO_4) _2 : Eu ~ ( 3 ) red phosphor preparation

Author ZhangYongSheng
Tutor JiaoHuan
School Shaanxi Normal University
Course Materials Science
Keywords WLED AgGd WO4 2: Eu3 Tetragonal Luminescent properties Energy transfer
CLC O482.31
Type Master's thesis
Year 2010
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White LED has high luminous efficiency, energy saving, no radiation, no pollution, and many other advantages, is regarded as a rising star of the \One of the main ways to achieve white light emission phosphor conversion technology using rare earth luminescent materials converted into white light LED chip emits blue light / UV. But less developed white LED luminous efficiency of the red phosphor, can not meet the requirements, so we need to find new and efficient white LED with red phosphor. In this paper, a high temperature solid state reaction prepared AgGd (WO4) 2: Eu3 red fluorescent material, temperature and luminescent properties of its phase and doped with Mo6 and sensitizer the Tb3 of energy passing through the matrix improve their luminescent properties. The prepared AgGd 750 ~ 1100 ℃ high temperature solid-phase method (WO4) 2: Eu3, phase analysis showed AgGd (WO4) 2 monoclinic and tetragonal two structures, which tetragonal phase has not been reported in the literature; spectroscopy showed AgGd (WO4) 2: Eu3 in the near-UV and blue LED chip as an excitation source used as a red phosphor; AgGd (WO4) 2: luminous intensity of Eu3 the Eu3 doping and sintering temperature have a certain relationship, and the Quartet AgGd (WO4) 2: of Eu3 luminous intensity higher than the monoclinic AgGd (WO4) 2: Eu3 luminous intensity. To to improved AgGd (WO4) 2: Eu3 luminescence properties to AgGd, (WO4) 2: Eu3 in doping with the the W6 same sub-group of Mo6 phase analysis show that the Mo6 the doping did not change AgGd (WO4) 2 structure but when the the Mo6 doping amount is increased gradually AgGd (W1-yMoyO4) 2 unit cell volume decreases gradually; the a Mo6 doping helps improve AgGd (WO4) 2: of Eu3 the luminous intensity, Mo6, Eu3 doped amount decided AgGd (W1-yMoyO4) the luminous intensity. A AgGd (WO4) 2:, of Eu3, and AgGd (W0.7Mo0.3O4) 2: Eu3 luminous intensity can be further improved by incorporation of the sensitizer of Tb3. Spectroscopy showed, AgGd (WO4) 2: Tb3 AgGd (W0.7Mo0.3O4) 2: Tb3 of the emission spectrum of emission spectra characteristic of Tb3 AgGd (WO4) 2: Tb3 and AgGd (W0.7Mo0.3O4) 2 : Tb3 luminous intensity the Tb3 doping amount of a certain relationship. In AgGd (WO4) 2: Eu3 Tb3 and AgGd,, (W0.7Mo0.3O4) 2: Eu3 and Tb3 system, Eu3 and Tb3 characteristic emission peaks exist at the same time, weakened the Tb3 emission intensity due to the Eu3 added, while Eu3 emission intensity due to the addition of Tb3 enhanced presence of the Eu3 the energy transfer from Tb3 to this view is the spectroscopy and fluorescence lifetime support of the test results, and in AgGd (W0.7Mo0.3O4) 2: Eu3, Tb3 system energy transfer efficiency is greater than in the AgGd (WO4) 2: Eu3, Tb3 system energy transfer efficiency.

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