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LumiLab Department of Solid State Sciences
Ghent UniversityBelgium
iCom, Budva, MontenegroSeptember 4, 2015
Jonas J. Joos, Dirk Poelman, Philippe F. Smet
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Nonequivalent lanthanide defects: energy level modeling
Energy levels, a tool for spectroscopy
1
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
4f2 4f5d CT host*
many-body diagram
Pr3+
Energy levels, a tool for spectroscopy
1
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
4f2 4f5d CT host*
many-body diagram
Pr3+
Energy levels, a tool for spectroscopy
1
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
4f2 4f5d CT host*
many-body diagramone-electron diagram
Pr3+
Energy levels, a tool for spectroscopy
1
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
4f2 4f5d CT host*
many-body diagramone-electron diagramcharge-state transition level
Pr3+
Empirical energy level schemes
2
CaGa2S4
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Empirical energy level schemes
2
CaGa2S4
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Empirical energy level schemes
2
CaGa2S4
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
easy!
Multiple defects
3
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Easy: All lanthanide ions do the same
example: CaGa2S4
Harder: All lanthanides do the same
example: SrAl2O4
Hard: Some lanthanides act “special”
example: SrGa2S4
Sr1 Sr2
Eu2+ Ce3+
Multiple defects
3
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Easy: All lanthanide ions do the same
example: CaGa2S4
Harder: All lanthanides do the same
example: SrAl2O4
Hard: Some lanthanides act “special”
example: SrGa2S4
Sr1 Sr2
Eu2+ Ce3+
Site-selective PL spectroscopy
4
Eu2+
J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
Sr1 Sr2
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Site-selective PL spectroscopy
4
Eu2+
Ce3+
D. D. Jia, J. Lumin. 117, 170 (2006)
Sr1 Sr2
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Site-selective PL spectroscopy
4 J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
VB
Eu2+
Ce3+
Eu3+
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Site-selective PL spectroscopy
4 J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
VB
vacuum
EuSr1 EuSr2
Eu2+
Ce3+
Eu3+
Sr1 Sr2
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Two-site energy level scheme
5
Trivalent lanthanides
Sr1Sr2
J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Two-site energy level scheme
6
Divalent lanthanides
Sr1Sr2Sr1
Sr2
J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Two-site energy level scheme
7
Divalent lanthanides
J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Sr1Sr2
Two-site energy level scheme
7
Divalent lanthanides
J. Botterman, J. J. Joos, P. F. Smet, Phys. Rev. B 90, 085147 (2014)
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Multiple defects
3
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Easy: All lanthanide ions do the same
example: CaGa2S4
Harder: All lanthanides do the same
example: SrAl2O4
Hard: Some lanthanides act “special”
example: SrGa2S4
Sr1 Sr2
Eu2+ Ce3+
Multiple defects
3
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Easy: All lanthanide ions do the same
example: CaGa2S4
Harder: All lanthanides do the same
example: SrAl2O4
Hard: Some lanthanides act “special”
example: SrGa2S4
Sr1 Sr2
Eu2+ Ce3+
PL spectroscopy Eu2+ and Ce3+
8
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
energy (eV)
PL spectroscopy Eu2+ and Ce3+
8
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
energy (eV)
PL spectroscopy Eu2+ and Ce3+
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
8 energy (eV)
PL spectroscopy Eu2+ and Ce3+
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
8 energy (eV)
PL spectroscopy Eu2+ and Ce3+
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
8 energy (eV)
PL spectroscopy Eu2+ and Ce3+
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
8 energy (eV)
PL spectroscopy Eu2+ and Ce3+
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
8 energy (eV)
Local environment from EPR
9
SrGa2S4:Eu2+ SrGa2S4:Ce3+
W. L. Warren et al., Appl. Phys. Lett. 70, 478 (1997)
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
SrGa2S4:Ce3+
Repercussions on E-level scheme
10
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Repercussions on E-level scheme
10
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Multiple defects
3
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Easy: All lanthanide ions do the same
example: CaGa2S4
Harder: All lanthanides do the same
example: SrAl2O4
Hard: Some lanthanides act “special”
example: SrGa2S4
Sr1 Sr2
Eu2+ Ce3+
Conclusions
11
Realistic materials often require more complex models
Very distinct experimental features burried in uncertainty intervals
General physical insight most important merit
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
LumiLab Department of Solid State Sciences
Ghent UniversityBelgium
iCom, Budva, MontenegroSeptember 4, 2015
Jonas J. Joos, Dirk Poelman, Philippe F. Smet
Jonas Joos Nonequivalent lanthanide defects: energy level modeling
Nonequivalent lanthanide defects: energy level modeling
