Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7934612 | Progress in Natural Science: Materials International | 2018 | 7 Pages |
Abstract
Mn4+-activated oxide phosphors, owing to their desirable spectral features, eco-friendly and low cost, are emerging as a new class of non-rare-earth red phosphors for warm white LEDs. However, these phosphors possess low photoluminescence quantum efficiency excited by blue chip currently. Herein we report an isostructural solid solution of Ca14Zn6Ga10âxAlxO35: 0.15Mn4+ (0 ⤠x ⤠10) synthesized by a traditional solid-state reaction route. The microstructure and luminescent performance of this red-emitting phosphor are investigated in detail with the aids of X-ray diffraction, diffuse reflection spectra, photoluminescence spectra/decay/QE, and temperature-dependent PL/QE measurements. Blue shift of energy peaks of 4A2 â 4T1 and 4A2 â 4T2 transition is illustrated by the Tanabe-Sugano diagram and the configurational coordinate diagram. The crystal field strength (Dq) and the Racah parameters (B and C) are carefully calculated to estimate the nephelauxetic effect β respectively. Particularly we achieve external and internal quantum efficiencies as high as 26.1% and 40.3% for Ca14Zn6Ga6Al4O35: 0.15Mn4+ excited by 466â¯nm, the highest one ever reported in Mn4+ activated oxide phosphors under the similar condition.
Related Topics
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Materials Science
Electronic, Optical and Magnetic Materials
Authors
Yiyang Zhou, Weiren Zhao, Chongrui Lu, Zifeng Liao,