Publication Date:
2014-02-01
Description:
A single-phase multicolor emitting phosphor, Ca 3 Al 2 O 6 :Ce 3+ ,Li + , was prepared by a solid-state reaction. When the Ce 3+ concentration is lower than 0.030 (molar ratio in Ca 3 Al 2 O 6 ), yellow and greenish blue emissions can be observed under the excitation by a blue and a near UV light, respectively. The yellow-emitting phosphor possesses an internal quantum efficiency of 89%. Additional purplish blue emission turns up when Ce 3+ concentrations are higher than 0.040. Tunable emission bands are originated from Ce 3+ ions on different Ca sites in Ca 3 Al 2 O 6 . Although the emission band of purplish blue or greenish blue overlaps the excitation band of yellow emission, and the distances between the unlike Ce 3+ ions are in the range of electric dipole–dipole interaction, no energy transfer is observed. Furthermore, emission wavelengths for the yellow, greenish blue, and purplish blue emission show little change upon increasing Ce 3+ concentrations.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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