In:
Journal of the American Ceramic Society, Wiley, Vol. 101, No. 12 ( 2018-12), p. 5477-5486
Abstract:
Hydrothermal reaction at 150°C and pH = 10 for 24 hours crystallized (Gd, RE ) 2 ( OH ) 4 SO 4 layered hydroxide sulfate (monoclinic structure; RE = Pr, Tb), from which Gd 2 O 2 S: RE (hexagonal structure) green phosphor hexagons were derived via facile dehydration in flowing H 2 at 1200°C. Rietveld refinement of the XRD patterns yielded cell dimensions that confirmed the direct crystallization of solid solution. Photoluminescence ( PL ) study at room temperature found absolute quantum yields of ~25.1% and 28.4%, CIE chromaticity coordinates of (0.145, 0.679) and (0.326, 0.566), and fluorescence lifetimes of ~2.36 μs and 1.21 ms for Pr 3+ and Tb 3+ under 300 and 275 nm UV excitations, respectively. Temperature‐dependent PL analysis (25‐200°C) indicated that both the Pr 3+ ‐ and Tb 3+ ‐doped phosphors have favorably good thermal stability and retained ~65% and 80% at 100°C and ~41% and 47% at 200°C of their initial emission intensities, respectively. The activation energy for the thermal quenching of PL was determined to be ~0.221 (Pr 3+ ) and 0.314 eV (Tb 3+ ). Cathodoluminescence ( CL ) found that both the phosphors exhibit increasingly higher emission intensity/brightness at a higher acceleration voltage (up to 7 kV) or beam current (up to 50 μA) and are stable under electron bombardment in the studied range. Raising beam current was suggested to be more effective to enhance CL.
Type of Medium:
Online Resource
ISSN:
0002-7820
,
1551-2916
DOI:
10.1111/jace.2018.101.issue-12
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
2008170-4
detail.hit.zdb_id:
219232-9
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