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Single Crystalline Films of Ce 3+ -Doped Y 3 Mg x Si y Al 5−x−y O 12 Garnets: Crystallization, Optical, and Photocurrent Properties.
- Source :
- Materials (1996-1944); Mar2023, Vol. 16 Issue 5, p1869, 16p
- Publication Year :
- 2023
-
Abstract
- This research focuses on LPE growth, and the examination of the optical and photovoltaic properties of single crystalline film (SCF) phosphors based on Ce<superscript>3+</superscript>-doped Y<subscript>3</subscript>Mg<subscript>x</subscript>Si<subscript>y</subscript>Al<subscript>5−x−y</subscript>O<subscript>12</subscript> garnets with Mg and Si contents in x = 0–0.345 and y = 0–0.31 ranges. The absorbance, luminescence, scintillation, and photocurrent properties of Y<subscript>3</subscript>Mg<subscript>x</subscript>Si<subscript>y</subscript>Al<subscript>5−x−y</subscript>O<subscript>12</subscript>:Ce SCFs were examined in comparison with Y<subscript>3</subscript>Al<subscript>5</subscript>O<subscript>12</subscript>:Ce (YAG:Ce) counterpart. Especially prepared YAG:Ce SCFs with a low (x, y < 0.1) concentration of Mg<superscript>2+</superscript> and Mg<superscript>2+</superscript>–Si<superscript>4+</superscript> codopants also showed a photocurrent that increased with rising Mg<superscript>2+</superscript> and Si<superscript>4+</superscript> concentrations. Mg<superscript>2+</superscript> excess was systematically present in as-grown Y<subscript>3</subscript>Mg<subscript>x</subscript>Si<subscript>y</subscript>Al<subscript>5−x−y</subscript>O<subscript>12</subscript>:Ce SCFs. The as-grown SCFs of these garnets under the excitation of α–particles had a low light yield (LY) and a fast scintillation response with a decay time in the ns range due to producing the Ce<superscript>4+</superscript> ions as compensators for the Mg<superscript>2+</superscript> excess. The Ce<superscript>4+</superscript> dopant recharged to the Ce<superscript>3+</superscript> state after SCF annealing at T > 1000 °C in a reducing atmosphere (95%N<subscript>2</subscript> + 5%H<subscript>2</subscript>). Annealed SCF samples exhibited an LY of around 42% and similar scintillation decay kinetics to those of the YAG:Ce SCF counterpart. The photoluminescence studies of Y<subscript>3</subscript>Mg<subscript>x</subscript>Si<subscript>y</subscript>Al<subscript>5−x−y</subscript>O<subscript>12</subscript>:Ce SCFs provide evidence for Ce<superscript>3+</superscript> multicenter formation and the presence of an energy transfer between various Ce<superscript>3+</superscript> multicenters. The Ce<superscript>3+</superscript> multicenters possessed variable crystal field strengths in the nonequivalent dodecahedral sites of the garnet host due to the substitution of the octahedral positions by Mg<superscript>2+</superscript> and the tetrahedral positions by Si<superscript>4+</superscript>. In comparison with YAG:Ce SCF, the Ce<superscript>3+</superscript> luminescence spectra of Y<subscript>3</subscript>Mg<subscript>x</subscript>Si<subscript>y</subscript>Al<subscript>5−x−y</subscript>O<subscript>12</subscript>:Ce SCFs greatly expanded in the red region. Using these beneficial trends of changes in the optical and photocurrent properties of Y<subscript>3</subscript>Mg<subscript>x</subscript>Si<subscript>y</subscript>Al<subscript>5−x−y</subscript>O<subscript>12</subscript>:Ce garnets as a result of Mg<superscript>2+</superscript> and Si<superscript>4+</superscript> alloying, a new generation of SCF converters for white LEDs, photovoltaics, and scintillators could be developed. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19961944
- Volume :
- 16
- Issue :
- 5
- Database :
- Complementary Index
- Journal :
- Materials (1996-1944)
- Publication Type :
- Academic Journal
- Accession number :
- 162349685
- Full Text :
- https://doi.org/10.3390/ma16051869