Local Ce environments and their effects on optical properties of SrS phosphors

Warren, W. L.; Vanheusden, K.; Seager, C. H.; Tallant, D. R.; Tuchman, Judah A.; Silliman, S. D.; Brower, Daniel T.

doi:10.1063/1.363776

Cited by 21 publications

(23 citation statements)

References 18 publications

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“…Their presence around the magnetic ions significantly disturbs the original site symmetry. Previous results 11,24 on SrS doped with Ce 3+ ions are in line with the present study. It was established that the axial Ce 3+ sites were due to the existence of Sr vacancies near the Ce 3+ ions.…”

Section: Discussionsupporting

confidence: 94%

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EPR study of local symmetry sites ofCe3+inPb1−x
Gratens
¹
,
Bindilatti
²
,
Chitta
³

et al. 2009
Phys. Rev. B
7
1
6
0
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The local site symmetry of Ce 3+ ions in the diluted magnetic semiconductors Pb 1−x Ce x A ͑A = S, Se, and Te͒ has been investigated by electron-paramagnetic resonance ͑EPR͒. The experiments were carried out on single crystals with cerium concentration x ranging from 0.001 to 0.035. The isotropic line due to Ce 3+ ions located at the substitutional Pb cation site with octahedral symmetry was observed for all the studied samples. We determined the effective Landé factors to be g = 1.333, 1.364, and 1.402 for A = S, Se, and Te, respectively. The small difference with the predicted Landé factor g of 10/7 for the ⌫ 7 ͑J =5/ 2͒ ground state was attributed to crystal-field admixture. In addition, EPR lines from Ce 3+ ions located at sites with small distortion from the original octahedral symmetry were also observed. Two distinct sites with axial distortion along the ͗001͘ crystallographic direction were identified and a third signal in the spectrum was attributed to sites with the cubic symmetry distorted along the ͗110͘ direction. The distortion at these distinct Ce sites is attributed to Pb lattice vacancies near the cerium ions that compensate for its donor activity.

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Section: Discussionsupporting

confidence: 94%

“…[22][23][24] They are cation vacancies in nn or next-nearest-neighbor ͑nnn͒ site. They can also be impurity ions in substitution sites or interstitial anions.…”

Section: Discussionmentioning

confidence: 99%

EPR study of local symmetry sites ofCe3+inPb1−x
Gratens
¹
,
Bindilatti
²
,
Chitta
³

et al. 2009
Phys. Rev. B
7
1
6
0
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“…The density of the Ce 3ϩ sites were determined by computer analysis of the EPR line shapes for the two types of EPRactive Ce 3ϩ centers observed. 13,14 …”

Section: Methodsmentioning

confidence: 99%

Chromaticity and electroluminescent efficiency of atomic layer epitaxy SrS:Ce thin films

Warren

Seager

Soininen³

et al. 1998

Journal of Applied Physics

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We have studied various factors that control the luminous properties of atomic layer epitaxy ͑ALE͒ SrS:Ce electroluminescent ͑EL͒ devices by using electron paramagnetic resonance, photoluminescent decay, x-ray diffraction, and charge-voltage characterization. EL and PL light is green shifted in ALE SrS:Ce films, compared to powders and thin films prepared with some other techniques. The origin of the green shift is discussed. Moderate heat treatments of as-deposited SrS:Ce devices were found to dramatically improve the EL efficiency. This is due to the removal of defects leading to nonradiative Ce 3ϩ decay and to reduction of Ce 4ϩ to radiative Ce 3ϩ . Different heat treatments were found to influence the transferred charge, so that there is an optimal heat treatment temperature between 500 and 750°C. Heat treatments also induce macroscopic stress in these SrS:Ce films. This was seen to induce a local stress around Ce 3ϩ sites. However, the stresses were not found to directly correlate with the luminous efficiency. The SrS:Ce growth temperature was found to affect the Ce 3ϩ excitation efficiency in EL. Electronic traps in SrS:Ce films are discussed. We suggest that some traps can be beneficial in providing necessary charge for the Ce 3ϩ excitation process and others can be deleterious in that they suppress radiative Ce 3ϩ decay events.To determine the effects of Ce doping, undoped SrS films were also deposited and fully characterized. Finally, we compare the properties of films prepared by ALE to those deposited via rf sputtering.

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“…In this scheme, the Ce 3ϩ ion is compensated by one next nearest neighbor strontium vacancy with a charge of 2 Ϫ . Evidence for this argument was observed from EPR studies of SrS:Ce powder [8], as well as sputtered and MBE grown SrS:Ce samples [5]. On the other hand, the doping of monovalent Cu on a divalent Sr site is expected to promote the introduction of sulfur vacancies (V S ) to maintain charge neutrality.…”

Section: Charge Compensation and Thermal Quenching Of Srs:cu Ymentioning

confidence: 99%

Codoping studies of physical vapor phase deposition of SrS:Cu

et al. 2000

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A series of charge compensation investigations on SrS:Cu grown by physical vapor phase are reported. In this study, the trivalent ion, Y, was codoped during SrS growth to substitute on the Sr-site. Although similar EL performance to high temperature annealed sputtered samples was obtained using an annealing temperature of 650ЊC, our results indicated that the thermal quenching in this material could only be reduced by charge compensation codoping. Preliminary results show that at 300 K the brightness of SrS:Cu, Y was only 15% less than at 10 K. From temperature dependent PL, and high resolution PLE, the physical properties of the defect and the defect reduction mechanisms are determined. ᭧

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Local Ce environments and their effects on optical properties of SrS phosphors

Cited by 21 publications

References 18 publications

EPR study of local symmetry sites ofCe3+inPb1−x
Gratens
¹
,
Bindilatti
²
,
Chitta
³

et al. 2009
Phys. Rev. B
7
1
6
0
View full text Add to dashboard Cite

EPR study of local symmetry sites ofCe3+inPb1−x
Gratens
¹
,
Bindilatti
²
,
Chitta
³

et al. 2009
Phys. Rev. B
7
1
6
0
View full text Add to dashboard Cite

Chromaticity and electroluminescent efficiency of atomic layer epitaxy SrS:Ce thin films

Codoping studies of physical vapor phase deposition of SrS:Cu

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Local Ce environments and their effects on optical properties of SrS phosphors

Cited by 21 publications

References 18 publications

EPR study of local symmetry sites ofCe3+inPb1−xGratens1, Bindilatti2, Chitta3 et al. 2009Phys. Rev. B7160View full textAdd to dashboardCite

EPR study of local symmetry sites ofCe3+inPb1−xGratens1, Bindilatti2, Chitta3 et al. 2009Phys. Rev. B7160View full textAdd to dashboardCite

Chromaticity and electroluminescent efficiency of atomic layer epitaxy SrS:Ce thin films

Codoping studies of physical vapor phase deposition of SrS:Cu

Contact Info

Product

Resources

About

EPR study of local symmetry sites ofCe3+inPb1−x
Gratens
¹
,
Bindilatti
²
,
Chitta
³

et al. 2009
Phys. Rev. B
7
1
6
0
View full text Add to dashboard Cite

EPR study of local symmetry sites ofCe3+inPb1−x
Gratens
¹
,
Bindilatti
²
,
Chitta
³

et al. 2009
Phys. Rev. B
7
1
6
0
View full text Add to dashboard Cite