Local structure of the Ce3+ ion in the yellow emitting phosphor YAG:Ce

Ghigna, Paolo; Pin, Sonia; Ronda, Cees; Speghini, Adolfo; Piccinelli, Fabio; Bettinelli, Marco

doi:10.1016/j.optmat.2011.07.015

Cited by 35 publications

(23 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This makes it a versatile tool to study persistent luminescent materials since the dopant concentration will usually be very low. [18][19][20][21][22][23][24][25][26][27][28] …”

Section: Introductionmentioning

confidence: 99%

The importance of inversion disorder in the visible light induced persistent luminescence in Cr³⁺doped AB₂O₄(A = Zn or Mg and B = Ga or Al)

Basavaraju

Priolkar

Gourier

et al. 2015

Phys. Chem. Chem. Phys.

131

110

View full text Add to dashboard Cite

Cr 3+ doped spinel compounds AB 2 O 4 with A=Zn, Mg and B=Ga, Al exhibit a long near infrared persistent luminescence when excited with UV or X-rays. In addition, persistent luminescence of ZnGa 2 O 4 and to a lesser extent MgGa 2 O 4 , can also be induced by visible light excitation via 4 A 2 → 4 T 2 transition of Cr 3+ , which makes these compounds suitable as biomarkers for in vivo optical imaging of small animals. We correlate this peculiar optical property with the presence of antisite defects, which are present in ZnGa 2 O 4 and MgGa 2 O 4 . By using X-ray absorption fine structure (XAFS) spectroscopy, associated with electron paramagnetic resonance (EPR) and optical emission spectroscopy, it is shown that an increase in antisite defects concentration results in a decrease in the Cr-O bond length and the octahedral crystal field energy. A part of the defects are in the close environment of Cr 3+ ions, as shown by the increasing strain broadening of EPR and XAFS peaks observed upon increasing antisite disorder. It appears that ZnAl 2 O 4 , which exhibits the largest crystal field splitting of Cr 3+ and the smallest antisite disorder, does not show considerable persistent luminescence upon visible light excitation as compared to ZnGa 2 O 4 and MgGa 2 O 4 . These results highlight the importance of Cr 3+ ions with neighboring antisite defects in the mechanism of persistent luminescence exhibited by Cr 3+ doped AB 2 O 4 spinel compounds.

show abstract

“…This makes it a versatile tool to study persistent luminescent materials since the dopant concentration will usually be very low. [18][19][20][21][22][23][24][25][26][27][28] …”

Section: Introductionmentioning

confidence: 99%

The importance of inversion disorder in the visible light induced persistent luminescence in Cr³⁺doped AB₂O₄(A = Zn or Mg and B = Ga or Al)

Basavaraju

Priolkar

Gourier

et al. 2015

Phys. Chem. Chem. Phys.

131

110

View full text Add to dashboard Cite

show abstract

“…2 F 7/2 (7) transition, that leads to the apparent two band emission shape for main center emission of Ce 3+ in garnets, has been explained in terms of higher symmetry of the crystal field; the crystal field in garnets being of the order of spin-orbit $2000 cm À1 [1][2][3][4][5][6]. The assumed higher symmetry of the vicinity of Ce 3+ in YAG is sustained by EXAFS data [27]. Since Ce 3+ has in 8-fold coordination larger ionic radius compared to Y 3+ [28], in Ce:YAG crystal a significant expansion of the distorted cubic local structure (limited to the nearest neighbors coordination O 2À sphere) takes place.…”

Section: Discussionmentioning

confidence: 85%

Multicenters in Ce3+ visible emission of YAG ceramics

Lupeǐ

Gheorghe

et al. 2014

Optical Materials

View full text Add to dashboard Cite

“…15]. In effect, in the case of the Ce Y single substitutional defect, wave function based ab initio embedded-cluster calculations on the states of the 4f 1 and 5d 1 configurations (completeactive-space self-consistent-field [16][17][18] based second-order many-body perturbation theory [19][20][21][22] CASSCF/CASPT2) predicted its ground structure (later seen to agree reasonably well with EXAFS measurements 23 ) and excited state structures, and computed its absorption and emission spectra, which helped solving remaining assignment issues 24 . In the cases of Ga 3+…”

Section: Introductionmentioning

confidence: 81%

Antisite defects in Ce-doped YAG (Y3Al5O12): first-principles study on structures and 4f–5d transitions

2012

View full text Add to dashboard Cite

The interactions between Ce 3+ and antisite defects (AD) in YAG (Y 3 Al 5 O 12 ) are studied by means of first-principles calculations: Periodic-boundary-conditions density-functional-theory for a 160 atom YAG unit cell with one Ce 3+ and one or two ADs, and complete-active-space secondorder perturbation theory for the 4f 1 , 5d 1 , and 6s 1 electronic manifolds of the (CeO 8 Al 2 O 4 ) 15− embedded cluster. Attractive interactions are found between Ce 3+ and the ADs. The formation of one AD is more favorable in Ce:YAG than in YAG, but the formation of a second AD is less favorable, which means that the presence of Ce tends to lower the concentration of antisite defects in YAG. The interaction between Ce 3+ and antisite defects blueshifts the two lowest Ce 3+ 4f → 5d transitions. This result rules out the involvement of antisite defects in the recently reported excitation of the lowest 5d → 4f emission with photons below the zero-phonon line and leaves other distorted Cerium centers for consideration, like Ce 3+ interacting with interstitial nonstoichiometric Yttrium or with vacancies. The reasons behind the blueshifts are analyzed in detail:They are dominated by a decrease in the effective ligand-field splitting of the 5d 1 manifold, almost entirely due to the structural changes of short-and long-range and with almost negligible electronic effects from the Y and Al site exchanges.

show abstract

Local structure of the Ce3+ ion in the yellow emitting phosphor YAG:Ce

Cited by 35 publications

References 12 publications

The importance of inversion disorder in the visible light induced persistent luminescence in Cr³⁺doped AB₂O₄(A = Zn or Mg and B = Ga or Al)

The importance of inversion disorder in the visible light induced persistent luminescence in Cr³⁺doped AB₂O₄(A = Zn or Mg and B = Ga or Al)

Multicenters in Ce3+ visible emission of YAG ceramics

Antisite defects in Ce-doped YAG (Y3Al5O12): first-principles study on structures and 4f–5d transitions

Contact Info

Product

Resources

About

Local structure of the Ce3+ ion in the yellow emitting phosphor YAG:Ce

Cited by 35 publications

References 12 publications

The importance of inversion disorder in the visible light induced persistent luminescence in Cr3+doped AB2O4(A = Zn or Mg and B = Ga or Al)

The importance of inversion disorder in the visible light induced persistent luminescence in Cr3+doped AB2O4(A = Zn or Mg and B = Ga or Al)

Multicenters in Ce3+ visible emission of YAG ceramics

Antisite defects in Ce-doped YAG (Y3Al5O12): first-principles study on structures and 4f–5d transitions

Contact Info

Product

Resources

About

The importance of inversion disorder in the visible light induced persistent luminescence in Cr³⁺doped AB₂O₄(A = Zn or Mg and B = Ga or Al)

The importance of inversion disorder in the visible light induced persistent luminescence in Cr³⁺doped AB₂O₄(A = Zn or Mg and B = Ga or Al)