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1988Carnall, Goodman
Rajnak, Rana
Ln3+
20,000 cm-1
500 nm2.5 eV
2
3
Application: Telecommunications
Kenyon Progr Quantum Electron 26 (2002) 225
Loss spectrum of silica optical fiber in near-IR region
low loss
Er3+ emission in silica host
Er3+ and Sicryst: semiconductor host
injection of e-h pairs
trap
carrier recombin-ation
Auger transfer to free carriers
back-transfer
EDFA
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Application: Lasers...
http://www.youtube.com/watch?v=CZNFdr4d7g4
http://en.wikipedia.org/wiki/File:YAG2.svg
Nd:YAG
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Rare earth doped LED with different emitting colors
Application: Phosphors for WLED
WLED
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VUV: (147,172 nm) to visible (450-610nm)
Application: Phosphors for VUV plasma display
plasma display
PDP
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Application: Scintillators and dosemeters
• γ-ray detection, for medical diagnostic imaging etc• Fast 5d → 4f emission of Ce3+ ( ~ 10-70 ns)
• LuI3:Ce3+, with a light yield of 95000 photons per MeV [Krämer]
• and for Ce3+ doped into elpasolite hosts such as Cs2LiYBr6 [Bessiere].
LaCl3:Ce3+LaBr3:Ce3+
Lee IEEE Trans Nucl Sci 52 (2005) 1119
Wojtowicz IEEE Trans Nucl Sci 43 (1996) 2168
Krämer J. Mater. Chem. 16 (2006) 2773
Bessiere IEEE Trans Nucl Sci 51 (2004) 2970
NaI:Tl BGO
Detector
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Si
Si2 (e-+h+)
Down-conversion
Downconversion layer
Application: Quantum cutting for Photovoltaics
-Improving the efficiency of conversion of solar
energy into electricity
hν > 2Eg (Si)hν’ >= Eg
陈永虎博士 2009 nsfc项目和尹民教授的 2010 nsfc项目均与此相关
Solar Energy
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Applications: Sensors
Usually Ln3+ complex emission in solution is not quenched by O2.
Eu(DPIQ)(TTA)3
in MCM41 composites
10 mg/g
20 mg/g
30 mg/g
Eu3+*+O2 → Eu3+ + O2*
Zuo J Solid St Chem 183 (2010) 1715
Sensors
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Applications: Biomarkers
NH
+HN
H+N
N+H
OH
N
H+NH3C
3Cl-
Hoechst 33258 - NucleusWeakness: UV-Excitation, Broad Emission Range (400-660 nm)
O
SO2NHCH2CH2NH C
O
(H3C)2N
F F
F
F F
(E)
(Z)N
E12353 Endoplasmic Reticulum TrackerWeakness: Expensive 150GBP 2.5g UV-Excitation Staining ER only few minutes
NH
C NH2
N+H2
CH2N
N+H2
2 Cl-
D1306 4',6-diamidino-2-phenylindole, dihydrochloride (DAPI)
DNA and RNA Staining Weakness: UV-Excitation Broad Emission Bands
Commercial Available Markers
O N+(CH3)2Cl-(H3C)2N
CH2Cl
Orange CMTMRos M7510-Mitochrondria Tracker
Weakness: UV-Excitation, Broad Emission Range (550-700 nm)
www.probes.invitrogen.com
Biomarkers
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Theory: Lanthanide ions in crystals
6p
6s5d
4f
5p5s
Empty
Full
E
VB
CB
Example: 4f6
Eu3+ or Sm2+
4f-4f
4f-5dCT
Ionization
Host Ln3+ or Ln2+
“Crystal field”
Trapping electrons, holes or excitons, and modifying vibration
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Theory : Ln3+ in complex
(octahedral site, not to scale)
• Energies for Multi-electron levels: (crystal-field model and/or ab initio calculations)
• Transition Intensities: Strongly dependent on the
ligands surrounding the lanthanide ion.
eg
ligand π
f
d
f- d π- d
f- f
a2u
t2u
t1u
t2g
π- f
ligand π*
π- π*
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Experiments
• Synthesis• Raman, FTIR, XRD, AFM,EDX etc.• Optical properties:
– Light source: Nd3+@YAG + OPA; blackbody radiator lamp; Synchrotron radiation; Ultra short pulse laser
– Cryostat (Down to ~2K)– Detectors: PMT or CCD and fast response detectors– Refractive index measurements
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VUV Spectroscopy
Synchrotron
Sample
Excitation MC
Emission MC
MC: Monochromator
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Contents
Electrons, states, energy levels
Allowed Transitions
Forbidden transitions
Nonradiative process
Energy transfer
Some applications