单基质白光荧光粉的制备方法

3 Summary and outlook
2
1
Introduction
3
1 Introduction displays
lighting
significant power saving
WLEDs Longer
lifetime
environmental friendliness
solar cells
Adv. Funct. Mater., 2010, 20, 3446–3456.
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2.2 Multiple ions co-doping in a single host
LaOCl:Tb3+、Sm3+
LaOCl:Tm3+、Dy3+
The CL spectrum of an LaOCl:0.01Tb3+, 0.005Sm3+ The CL spectrum of LaOCl:0.002Tm3+,0.02Dy3+ under
Dependence of emission spectra of (Ca0.993-x-yMgxSry)9Y(PO4)7: 0.007Eu2+ phosphors on concentrations of Mg2+ and Sr2+
J. Mater. Chem., 2011, 21, 104897–10495.
(a) Spectral overlap between the Eu2+ PL spectrum (solid line) and
the Mn2+ PLE spectrum (dashed line); (b) the emission spectra of
(Ca0.993-x)9Gd(PO4)7:0.007Eu2+, xMn2+ phosphors under near-UV CIE chromaticity diagram of CGP:0.007Eu2+, xMn2+
Studies on producing white light in a single-phase host
Contents
1 Introduction 2 Approaches to realize white-light emission in
a single-phase host material
strong reabsorption， Low luminescent efficiency ， complicated device and the color balance is difficult to control.
LED-based and LED-plus-phosphor-based approaches for white light sources implemented as di-, tri-, and tetrachromatic sources.
2.2 Multiple ions co-doping in a single host
LaOCl:RE3+
(RE = Eu,Tb, Sm, Tm, Dy )
Eu3+(5D0,1,2→7F0,1,2,3,4, red) Tb3+(5D3,4 →7F2,3,4,5,6, blue-green) Sm3+(4G5/2 →6H5/2,7/2,9/2, orange-red) Tm3+ (1D2, 1G4-3F4, 3H6, blue) Dy3+ (4F9/2-6H15/2, 6H13/2,yellow)
Typical photoluminescence spectra of Ca1-xIn2O4:xEu3+ with different Eu3+ ions concentrations (a) and the corresponding CIE chromaticity diagram (b)
J. Phys. Chem. C, 2007, 111, 16601–16607. 9
2.1 Single activator ion doped systems
BaSrMg(PO4)2:Eu2+
Eu2+ occupying Sr2+
Eu2+ occupying Ba2+
Disadvantage：the obtained white light lack a red component, resulting in the lower CRI.
single-phase white light emission materials
higher CRI, tunable CCT，weak reabsorption， higher luminous efficiency
Science., 2005,308:1274-1278.
2
Approaches to realize white-light emission in a single-phase host material
sample. Inset, its luminescent photograph.
electron beam excitation. The inset shows a photograph
பைடு நூலகம்
of the sample with white light emission.
Opt. Lett.,2009, 34, 3833–3835.
J. Mater. Chem., 2009, 19, 8936–8943.
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2.3 Energy transfer approach
(Ca0.993-x)9Gd(PO4)7:0.007Eu2+, xMn2+
D A
The process of energy transfer from donor to acceptor
Adv. Funct. Mater., 2003, 13, 511–516.
1 Introduction
Red+Green+Blue=White Blue+Yellow=White
poor color rendering index, low stability of color temperature
Excitation spectra (a: λem = 447, b: λem = 536 nm) and emission spectra (c) (λex = 350 nm) of Ba0.97Sr0.99Mg(PO4)2:0.04Eu2+ powder
如何确定掺杂Ba和Sr的比例？
J. Alloys Compd., 2010, 498, 139–142.
communication
higher luminous efficiency
and brightness
White light luminescent materials are applied for a wide variety of applications.
White light-emitting diodes （ WLEDs ） are the most promising white-light source.
The color rendering index (CRI or Ra) definition is
based on comparing the color of test objects when illuminated by the light source under test, to the colors of the objects illuminated by a reference source.
8
2.1 Single activator ion doped systems
B. Eu3+-activated systems.
Ca1-xIn2O4:xEu3+
The diagram showing the basic conditions and process for Eu3+ to emit white light in single host lattices. DE is the energy difference between the involved levels; νmax is the highest available vibrational frequencies of the surroundings of the Eu3+ ion.
Typical CL spectra of LaOCl: Ln 3+. a) LaOCl: 0.8 mol% Tb 3+ , 3 mol% Eu 3+ ; b) LaOCl: 4 mol% Tb 3+ ,5 mol% Eu 3+ ; c) LaOCl: 0.5 mol% Tm 3+ , 2 mol% Eu 3 + ; d) LaOCl: 0.5 mol%Tm 3 + , 2 mol% Sm 3+ , and e) LaOCl: 1 mol% Tm 3+ , 2 mol% Tb 3+ , 2 mol%Eu 3+ . The insets are their corresponding CL digital photographs.
Color online CIE chromaticity diagram for Sr3B2O6 :m%Ce3+,n%Eu3+ excited at 351 nm. 1 m=1, n=0; 2 m=1, n=0.1; 3 m=1, n=0.15; 4 m=1, n=0.20; 5 m=1, n=0.25; 6 m=1, n=0.7; and 7 m=0, n=1. The Ce:YAG and GaN based white-emitting systems are compared with this work and portrayed in red line.
(a) PL and PLE spectra for Sr3B2O6:1% Ce3+, n% Eu2+ (n = 0.15). Inset:the conversion efficiency under UV excitation. (b) PL spectra for Sr3B2O6:1%Ce3+, n% Eu2+ phosphors excited at 351 nm. Inset: dependence of the energy transfer efficiency ηT on Eu2+ content n .
J. Phys. Chem. C, 2010, 114, 18698–18701.
insets show CGP:0.007Eu2+,xMn2+ phosphors irradiated under
365 nm UV lamp box
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2.3 Energy transfer approach
Sr3B2O6:Ce3+, Eu2+
LaOCl: xEu3+ (Sm 3 + ), yTb3+ , zTm3+
a) The CL digital photographs of LaOCl: xEu3+ , yTb3+ , zTm3+ samples. Arrow A, B, C and D represent the co-doping of Eu/Tb (high Tb3+ concentration), Eu/Tb (moderateTb3+ concentration), Eu/Tm and Tm/Sm in the LaOCl host, respectively. b) Solid-lined triangle and dash-lined triangle depict the tunable color region of LaOCl: Eu3+ , Tb3+ , Tm3+ and LaOCl: Sm3+ , Tb3+ , Tm3+ phosphors, respectively.
380 nm excitation
phosphorsunder 380 nm excitation: (1) x = 0; (2) x = 0.01; (3) x = 0.02; (4) x = 0.03;(5) x = 0.05; (6) x = 0.07; and (7) x = 0.1. The
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2.1 Single activator ion doped systems
A. Eu2+ doped systems.
435nm
(Ca0.993-x-yMgxSry)9Y(PO4)7: 0.007Eu2+
486nm 508nm
Mg2+↑ Sr2+↑
Dq
Mg2+
Dq
Ca2+
Sr2+
Partial energy level diagram of Eu2+ ion