Belgian Physical Society (BPS) meeting 2015, Liège. Results published in Physical Review B: http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.085147

1. jonas.joos@UGent.be
Belgian Physical Society, Liège
May 13, 2015
Energy level modeling of lanthanide defects in
SrAl2O4:Eu2+
Jonas Joos
Jonas Joos SrAl2O4:Eu2+, electronic structure

2. 1.Lanthanide luminescence

3. Lanthanide ions
1
Jonas Joos SrAl2O4:Eu2+, electronic structure

4. Lanthanide ions
1
Jonas Joos SrAl2O4:Eu2+, electronic structure

5. OFF ON
Technological applications
Conversion phosphor
2
Jonas Joos SrAl2O4:Eu2+, electronic structure

6. OFF ON
Technological applications
Conversion phosphor
2
Jonas Joos SrAl2O4:Eu2+, electronic structure

7. Technological applications
Conversion phosphor
2
Jonas Joos SrAl2O4:Eu2+, electronic structure

8. Jonas Joos Green phosphors for high brightness applications
Lanthanides
Electronic transitions
Li6Gd(BO3)3:Tb3+
F. Zhang et al., Physics Procedia 29 (2012), 55-61
3
Jonas Joos SrAl2O4:Eu2+, electronic structure

9. Lanthanides
Electronic transitions
Li6Gd(BO3)3:Tb3+
F. Zhang et al., Physics Procedia 29 (2012), 55-61
3
Jonas Joos SrAl2O4:Eu2+, electronic structure

10. Lanthanides
Electronic transitions
Li6Gd(BO3)3:Tb3+
4fN – 4fN transitions
F. Zhang et al., Physics Procedia 29 (2012), 55-61
3
Jonas Joos SrAl2O4:Eu2+, electronic structure

11. Lanthanides
Electronic transitions
Li6Gd(BO3)3:Tb3+
4fN – 4fN transitions
4fN – 4fN-15d1 transitions
F. Zhang et al., Physics Procedia 29 (2012), 55-61
3
Jonas Joos SrAl2O4:Eu2+, electronic structure

12. Lanthanides
Electronic transitions
Li6Gd(BO3)3:Tb3+
4fN – 4fN transitions
4fN – 4fN-15d1 transitions
Charge transfer transitions
F. Zhang et al., Physics Procedia 29 (2012), 55-61
3
Jonas Joos SrAl2O4:Eu2+, electronic structure

13. Lanthanides
Electronic transitions
Li6Gd(BO3)3:Tb3+
4fN – 4fN transitions
4fN – 4fN-15d1 transitions
Charge transfer transitions
host related
F. Zhang et al., Physics Procedia 29 (2012), 55-61
3
Jonas Joos SrAl2O4:Eu2+, electronic structure

14. 2.Energy level modeling: empirical approach

15. Empirical modeling of lanthanide materials
Ground state configuration
NN Ln Lanthanide Q = +II Q = +III
0 La Lanthanum [Xe]5d1
1 Ce Cerium [Xe]4f 2 [Xe]4f 1
2 Pr Praseodymium [Xe]4f 3 [Xe]4f 2
3 Nd Neodymium [Xe]4f 4 [Xe]4f 3
4 Pm Promethium [Xe]4f 5 [Xe]4f 4
5 Sm Samarium [Xe]4f 6 [Xe]4f 5
6 Eu Europium [Xe]4f 7 [Xe]4f 6
7 Gd Gadolinium [Xe]4f 75d1 [Xe]4f 7
8 Tb Terbium [Xe]4f 9 [Xe]4f 8
9 Dy Dysprosium [Xe]4f 10 [Xe]4f 9
10 Ho Holmium [Xe]4f 11 [Xe]4f 10
11 Er Erbium [Xe]4f 12 [Xe]4f 11
12 Tm Thulium [Xe]4f 13 [Xe]4f 12
13 Yb Ytterbium [Xe]4f 14 [Xe]4f 13
14 Lu Lutetium [Xe]4f 14
4
Jonas Joos SrAl2O4:Eu2+, electronic structure

16. Empirical modeling of lanthanide materials
Excited states
4
Jonas Joos SrAl2O4:Eu2+, electronic structure

17. Jonas Joos Green phosphors for high brightness applications
Empirical modeling of lanthanide materials
Location of the lowest 5d level
Spectroscopic redshift:
P. Dorenbos, Journal of Solid State Sci. and Technol. 2 (2013), R3001-R3011
5
Jonas Joos SrAl2O4:Eu2+, electronic structure

18. Empirical modeling of lanthanide materials
Energy of charge transfer (CT)
Charge transfer: Ln3+ + XQ- → Ln2+ + X(Q-1)-
6
Jonas Joos SrAl2O4:Eu2+, electronic structure

19. 3.Electronic structure and persistent
luminescence of SrAl2O4:LnQ+

20. SrAl2O4:Eu2+,Dy3+
Persistent luminescence
7
Jonas Joos SrAl2O4:Eu2+, electronic structure

21. SrAl2O4:Eu2+,Dy3+
Persistent luminescence
7
Jonas Joos SrAl2O4:Eu2+, electronic structure

22. SrAl2O4:Eu2+,Dy3+
Persistent luminescence
7
Jonas Joos SrAl2O4:Eu2+, electronic structure

23. SrAl2O4:Eu2+,Dy3+
Persistent luminescence
7
Jonas Joos SrAl2O4:Eu2+, electronic structure

24. SrAl2O4:Eu2+,Dy3+
Persistent luminescence
7
Iedereen wil naar lichtgevende Maria – p. 12
Jonas Joos SrAl2O4:Eu2+, electronic structure

25. SrAl2O4:Eu2+
Photoluminescence
emissionintensity(a.u.)
8
Jonas Joos SrAl2O4:Eu2+, electronic structure

26. SrAl2O4:Eu2+
Photoluminescence
emissionintensity(a.u.)
8
Jonas Joos SrAl2O4:Eu2+, electronic structure

27. SrAl2O4:Eu2+
Photoluminescence @ 10 K
520 nm
445 nm
8
Jonas Joos SrAl2O4:Eu2+, electronic structure

28. Jonas Joos Green phosphors for high brightness applications
SrAl2O4:Eu2+
Energy level modeling of 4f65d1 configuration
Free Eu2+ ion
4f6 5d1
(free)c
central field RS so cf(ff) (f) (f)   
RS so cf(fd) (d) (d)  
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

29. SrAl2O4:Eu2+
Energy level modeling of 4f65d1 configuration
Free Eu2+ ion
4f6 5d1
c
(free)c
RS so cf(fd) (d) (d)  
RScentral f sield o cf(ff) (f) (f)  
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

30. SrAl2O4:Eu2+
cfs
Free Eu2+ ion
4f6 5d1
(free)c
Energy level modeling of 4f65d1 configuration
c
RScentral f sield o cf(ff) (f) (f)  
RS so cf(fd) (d (d) ) 
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

31. SrAl2O4:Eu2+
Free Eu2+ ion
4f6 5d1
(free)c
Energy level modeling of 4f65d1 configuration
c
RScentral f sield cfo(ff) (f) (f)  
RS so cf(fd) (d (d) ) 
cfs
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

32. SrAl2O4:Eu2+
Free Eu2+ ion
4f6 5d1
(free)c
Energy level modeling of 4f65d1 configuration
c
RScentral f sield cfo(ff) (f) (f)  
RS so cf(fd) (d (d) ) 
decoupled scheme:
d f(f) (d)   1 1
f d   
f dE E E 
cfs
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

33. SrAl2O4:Eu2+
Free Eu2+ ion
4f6 5d1
(free)c
Energy level modeling of 4f65d1 configuration
c
RScentral f sield cfo(ff) (f) (f)  
RS so cf(fd) (d (d) ) 
decoupled scheme:
d f(f) (d)   1 1
f d   
f dE E E 
4f6 core: similar to Eu3+:
7
F
6J 
0J 
cfs
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

34. SrAl2O4:Eu2+
cfs
Free Eu2+ ion
4f6 5d1
(free)c
cfs (free)
Energy level modeling of 4f65d1 configuration
c
RScentral f sield cfo(ff) (f) (f)  
RS so cf(fd) (d (d) ) 
decoupled scheme:
d f(f) (d)   1 1
f d   
f dE E E 
4f6 core: similar to Eu3+:
7
F
6J 
0J 9
Jonas Joos SrAl2O4:Eu2+, electronic structure

35. SrAl2O4:Eu2+
Energy (eV)
Free Eu2+ ion
4f6 5d1
(free)c
5.0
4.0
3.0
cfs (free)
Energy level modeling of 4f65d1 configuration
 c blue
 cfs blue
central field RS so cf(ff) f (f)( )  
RS so cf(fd) (d (d) ) 
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

36. SrAl2O4:Eu2+
Energy (eV)
Free Eu2+ ion
4f6 5d1
(blue)D
(free)c
5.0
4.0
3.0
cfs (free)
Energy level modeling of 4f65d1 configuration
central field RS so cf(ff) f (f)( )  
RS so cf(fd) (d (d) ) 
 cfs blue
 c blue
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

37. SrAl2O4:Eu2+
Energy (eV) Energy (eV)
cfs (green)
Free Eu2+ ion
4f6 5d1
c (green)
(green)D
(free)c
4.0
3.0
5.0 5.0
4.0
3.0
cfs (free)
cfs (free)
Energy level modeling of 4f65d1 configuration
 cfs blue
(blue)D
 c blue
9
Jonas Joos SrAl2O4:Eu2+, electronic structure

38. SrAl2O4:Eu2+
Connection with crystallography
Monoclinic unit cell (P21)
Two nonequivalent Sr-sites (C1)
Sr1 Sr2
10
Jonas Joos SrAl2O4:Eu2+, electronic structure

39. SrAl2O4:Eu2+
Connection with crystallography
Monoclinic unit cell (P21)
Two nonequivalent Sr-sites (C1)
Empirical relations:
Prediction: Measurement
10
Jonas Joos SrAl2O4:Eu2+, electronic structure

40. SrAl2O4:Eu2+
Connection with crystallography
Monoclinic unit cell (P21)
Two nonequivalent Sr-sites (C1)
Empirical relations:
EuSr1: green emission
EuSr2: blue emission
10
Jonas Joos SrAl2O4:Eu2+, electronic structure

41. SrAl2O4:LnQ+
Lanthanide VRBE scheme - Input
VB
CB
Eu2+ lowest 4f
Eu3+ lowest 4f
Coulomb correlation energy for Eu2+/Eu3 obtained from Ce3+ spectrum:
P. Dorenbos, J. Lumin 135, 93 (2013)
D. Jia, J. Lumin. 117, 170 (2006)
11
Jonas Joos SrAl2O4:Eu2+, electronic structure

42. SrAl2O4:LnQ+
Lanthanide VRBE scheme - Input
VB
CB
Coulomb correlation energy for Eu2+/Eu3 obtained from Ce3+ spectrum:
P. Dorenbos, J. Lumin 135, 93 (2013)
D. Jia, J. Lumin. 117, 170 (2006)
11
Jonas Joos SrAl2O4:Eu2+, electronic structure

43. SrAl2O4:LnQ+
Lanthanide VRBE scheme - Input
VB
CB
Coulomb correlation energy for Eu2+/Eu3 obtained from Ce3+ spectrum
Chemical shift 4f level Eu2+ obtained:
P. Dorenbos, J. Lumin 135, 93 (2013)
D. Jia, J. Lumin. 117, 170 (2006)
11
Jonas Joos SrAl2O4:Eu2+, electronic structure

44. SrAl2O4:LnQ+
Lanthanide VRBE scheme - Input
VB
CB
Coulomb correlation energy for Eu2+/Eu3 obtained from Ce3+ spectrum
Chemical shift 4f level Eu2+ obtained:
Host referred binding energy from Eu3+ CT:
11
VB
vacuum
EuSr1 EuSr2
Jonas Joos SrAl2O4:Eu2+, electronic structure

45. SrAl2O4:LnQ+
Lanthanide VRBE scheme - Input
VB
CB
Coulomb correlation energy for Eu2+/Eu3 obtained from Ce3+ spectrum
Chemical shift 4f level Eu2+ obtained:
Host referred binding energy from Eu3+ CT:
11
VB
vacuum
EuSr1 EuSr2
Jonas Joos SrAl2O4:Eu2+, electronic structure

46. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

47. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

48. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

49. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

50. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

51. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

52. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

53. SrAl2O4:LnQ+
Lanthanide VRBE scheme
12
Jonas Joos SrAl2O4:Eu2+, electronic structure

54. SrAl2O4:LnQ+
Lanthanide VRBE scheme
Trivalent lanthanides
Sr1
Sr2
13
Jonas Joos SrAl2O4:Eu2+, electronic structure

55. SrAl2O4:LnQ+
Lanthanide VRBE scheme
Divalent lanthanides
Sr1
Sr2
13
Jonas Joos SrAl2O4:Eu2+, electronic structure

56. More info
14
Jonas Joos SrAl2O4:Eu2+, electronic structure

57. jonas.joos@UGent.be
Belgian Physical Society, Liège
May 13, 2015
Energy level modeling of lanthanide defects in
SrAl2O4:Eu2+
Jonas Joos
Jonas Joos SrAl2O4:Eu2+, electronic structure