Exciton interaction with Ce3+ and Ce4+ ions in (LuGd)3(Ga,Al)5O12 ceramics
(2021) In Journal of Luminescence 237.- Abstract
Scintillators based on Ce-doped garnets are regularly co-doped with Mg2+ or Ca2+ to form Ce ions in 4+ state and reduce undesired afterglow. However overly high Ce4+ concentration leads to poor light yield performance. In order to understand the reason for variation in luminescence efficiency of Ce3+- and Ce4+-doped garnets we investigate the differences in energy conversion processes in complex LuGd2Ga3Al2O12:Ce3+/Ce4+ ceramics by means of VUV synchrotron irradiation. At first we have established via transmission spectroscopy and X-ray absorption spectroscopy that... (More)
Scintillators based on Ce-doped garnets are regularly co-doped with Mg2+ or Ca2+ to form Ce ions in 4+ state and reduce undesired afterglow. However overly high Ce4+ concentration leads to poor light yield performance. In order to understand the reason for variation in luminescence efficiency of Ce3+- and Ce4+-doped garnets we investigate the differences in energy conversion processes in complex LuGd2Ga3Al2O12:Ce3+/Ce4+ ceramics by means of VUV synchrotron irradiation. At first we have established via transmission spectroscopy and X-ray absorption spectroscopy that LuGd2Ga3Al2O12:Ce, Mg sample contains cerium in the 4+ state only. Then we show with VUV spectroscopy efficient interaction of excitons with Gd3+ and Ce3+, and lack of exciton absorption edge in LuGd2Ga3Al2O12:Ce4+ excitation spectrum. Instead, Ce4+ exhibits charge-transfer absorption band in the range of exciton emission. We suggest that when Ce4+ concentration becomes too high, the exciton → Gd3+ → Ce3+ energy transfer path is hindered. It leads to high intensity of Gd3+ luminescence in Lu1Gd2Ga3Al2O12:Ce, Mg ceramics, but lowered Ce3+ X-ray excited luminescence. Fine balance between 3+ and 4+ Ce concentrations is necessary to achieve the best performance of garnet scintillators.
(Less)
- author
- organization
- publishing date
- 2021-09-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Ce, Energy transfer, Excitons, Garnet scintillators, Synchrotron, XANES
- in
- Journal of Luminescence
- volume
- 237
- article number
- 118150
- publisher
- Elsevier
- external identifiers
-
- scopus:85105321370
- ISSN
- 0022-2313
- DOI
- 10.1016/j.jlumin.2021.118150
- language
- English
- LU publication?
- yes
- id
- d4010ab5-1a9a-4233-8585-e7e13df3d51e
- date added to LUP
- 2021-05-25 16:13:38
- date last changed
- 2022-04-27 02:03:29
@article{d4010ab5-1a9a-4233-8585-e7e13df3d51e, abstract = {{<p>Scintillators based on Ce-doped garnets are regularly co-doped with Mg<sup>2+</sup> or Ca<sup>2+</sup> to form Ce ions in 4+ state and reduce undesired afterglow. However overly high Ce<sup>4+</sup> concentration leads to poor light yield performance. In order to understand the reason for variation in luminescence efficiency of Ce<sup>3+</sup>- and Ce<sup>4+</sup>-doped garnets we investigate the differences in energy conversion processes in complex LuGd<sub>2</sub>Ga<sub>3</sub>Al<sub>2</sub>O<sub>12</sub>:Ce<sup>3+</sup>/Ce<sup>4+</sup> ceramics by means of VUV synchrotron irradiation. At first we have established via transmission spectroscopy and X-ray absorption spectroscopy that LuGd<sub>2</sub>Ga<sub>3</sub>Al<sub>2</sub>O<sub>12</sub>:Ce, Mg sample contains cerium in the 4+ state only. Then we show with VUV spectroscopy efficient interaction of excitons with Gd<sup>3+</sup> and Ce<sup>3+</sup>, and lack of exciton absorption edge in LuGd<sub>2</sub>Ga<sub>3</sub>Al<sub>2</sub>O<sub>12</sub>:Ce<sup>4+</sup> excitation spectrum. Instead, Ce<sup>4+</sup> exhibits charge-transfer absorption band in the range of exciton emission. We suggest that when Ce<sup>4+</sup> concentration becomes too high, the exciton → Gd<sup>3+</sup> → Ce<sup>3+</sup> energy transfer path is hindered. It leads to high intensity of Gd<sup>3+</sup> luminescence in Lu<sub>1</sub>Gd<sub>2</sub>Ga<sub>3</sub>Al<sub>2</sub>O<sub>12</sub>:Ce, Mg ceramics, but lowered Ce<sup>3+</sup> X-ray excited luminescence. Fine balance between 3+ and 4+ Ce concentrations is necessary to achieve the best performance of garnet scintillators.</p>}}, author = {{Khanin, Vasilii and Venevtsev, Ivan and Chernenko, Kirill and Pankratov, Vladimir and Klementiev, Konstantin and van Swieten, Thomas and van Bunningen, Arnoldus J. and Vrubel, Ivan and Shendrik, Roman and Ronda, Cees and Rodnyi, Piotr and Meijerink, Andries}}, issn = {{0022-2313}}, keywords = {{Ce; Energy transfer; Excitons; Garnet scintillators; Synchrotron; XANES}}, language = {{eng}}, month = {{09}}, publisher = {{Elsevier}}, series = {{Journal of Luminescence}}, title = {{Exciton interaction with Ce<sup>3+</sup> and Ce<sup>4+</sup> ions in (LuGd)<sub>3</sub>(Ga,Al)<sub>5</sub>O<sub>12</sub> ceramics}}, url = {{http://dx.doi.org/10.1016/j.jlumin.2021.118150}}, doi = {{10.1016/j.jlumin.2021.118150}}, volume = {{237}}, year = {{2021}}, }