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https://doi.org/10.3938/NPSM.68.1196
Optical Properties of the Eu$^{2+}$ Doped Li$_2$SrSiO$_{4-\alpha}$N$_\alpha$
New Phys.: Sae Mulli 2018; 68: 1196~1202
Published online November 30, 2018;  https://doi.org/10.3938/NPSM.68.1196
© 2018 New Physics: Sae Mulli.

Purevdulam NAMKHAI1, Taeyoung KIM1, Hyun-Joo WOO1, Kiwan JANG*1, Jung Hyun JEONG2

1 Department of Physics, Changwon National University, Changwon 51140, Korea
2 Department of Physics, Pukyong National University, Busan 48513, Korea
Correspondence to: kwjang@changwon.ac.kr
Received September 14, 2018; Revised October 12, 2018; Accepted October 17, 2018.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Li$_2$Sr$_{1-x}$Eu$_x$SiO$_{4-\alpha}$N$_\alpha$ (Li$_2$SrSiO$_{4-\alpha}$N$_\alpha$:Eu$^{2+}$) phosphors were synthesized by using a solid state reaction (SSR) method with submicron Si$_3$N$_4$ and nano Si$_3$N$_4$ powders as the sources of Si and N, and the optical properties of those phosphors were studied. The studied phosphors showed efficient excitation characteristics over the broad range from 230 to 530 nm. Also, They showed broad emission spectra covering a range from 500 to 700 nm, with a peak at 568 nm, which was shifted longer wavelength by 18 nm as compared with that of commercial YAG:Ce$^{3+}$. Combined with a 450 nm blue LED chip, the results support the application of the Li$_2$SrSiO$_{4-\alpha}$N$_\alpha$:Eu$^{2+}$ phosphor as a luminescent material for a white-light source thaat is warmer than the commercial YAG:Ce$^{3+}$ white-light source. In addition, the Li$_2$SrSiO$_{4-\alpha}$N$_\alpha$ phosphors prepared from a submicron Si$_3$N$_4$ powder was found to emit a previously unreported self-activated luminescence in Li$_2$SrSiO$_{4-\alpha}$N$_\alpha$.
PACS numbers: 78.55.-m, 78.20.-e
Keywords: Li$_2$SrSiO$_{4-\alpha}$N$_\alpha$, Emission spectrum, Excitation spectrum, Solid state reaction method, Self-activated luminescence


November 2018, 68 (11)
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