Development of a Novel Green-Emitting Phosphate Phosphor KSrY(PO₄)₂:Eu²⁺

Akiko Saito, Hideki Kato, Makoto Kobayashi, Yasushi Sato, Masato Kakihana

Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan.

DOI: 10.4236/opj.2013.36A004                

Abstract

In this study, fluorescence characteristics were evaluated by synthesizing Eu²⁺ doped samples for phosphates of various compositions. The study led to a green light emitting KSrY(PO₄)₂:Eu²⁺, which is rare for a phosphate phosphor. KSrY(PO₄)₂:Eu²⁺ had an excitation band between 250 and 450 nm and emitted green light, reaching an emission maximum at 520 nm. As this result suggests that excitation by a near-ultraviolet LED is possible, KSrY(PO₄)₂:Eu²⁺ could be useful as a phosphor for white LEDs.

Keywords

Phosphate Phosphor; Eu²⁺-Activation; Green Emission

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	S. Lucas, E. Champion, D. Bregiroux, D. Bernache-Assollant and F. Audubert, “Rare Earth Phosphate Powders RePO4·nH2O (Re = La, Ce or Y). Part 1. Synthesis and Characterization,” Journal of Solid State Chemistry, Vol. 177, No. 4-5, 2004, pp. 1302-1311. http://dx.doi.org/10.1016/j.jssc.2003.11.003
[2]	Z. C. Wu, J.X. Shi, J. Wang, M.L. Gong and Q. Su, “A Novel Blue-Emitting Phosphor LiSrPO4:Eu2+ for White LEDs,” Journal of Solid State Chemistry, Vol. 179, No. 8, 2006, pp. 2356-2360. http://dx.doi.org/10.1016/j.jssc.2006.04.030
[3]	S. H. M. Poort, W. Janssen and G. Blasse, “Optical Properties of Eu2+-Activated Orthosilicates and Orthophosphates,” Journal of Alloys and Compounds, Vol. 260, No. 1-2, 1997, pp. 93-97. http://dx.doi.org/10.1016/S0925-8388(97)00140-0
[4]	Y. S. Tang, S. F. Hu, C. C. Lin, N. C. Bagkar and R. S. Liu, “Thermally Stable Luminescence of KSrPO4:Eu2+ Phosphor for White Light UV Light-Emitting Diodes,” Applied Physics Letters, Vol. 90, No. 4-5, 2007, Article ID: 151108. http://dx.doi.org/10.1063/1.2721846
[5]	C. Wan, J. Meng, F. Zhang, X. Deng and C. Yang, “An Efficient Blue-Emitting Phosphor LiCaPO4:Eu2+ for White LEDs,” Solid State Communications, Vol. 150, No. 31-32, 2010, pp. 1493-1495. http://dx.doi.org/10.1016/j.ssc.2010.05.037
[6]	X. Wang, F. Du, D. Wei, Y. Wuang and H. J. Seo, “The Blue-Emitting Phosphor of Eu2+-Doped Ca2Sr(PO4)2,” Journal of The Electrochemical Society, Vol. 158, No. 8, 2011, pp. J264-J268.
[7]	C. H. Huang, D. Y. Wang, Y. C. Chiu, Y. T. Yeh and T. M. Chen, “Sr8MgGd(PO4)7:Eu2+: Yellow-Emitting Phosphor for Application in Near-Ultraviolet-Emitting Diode Based White-Light LEDs,” RSC Advances, Vol. 2, No. 24, 2012, pp. 9130-9134. http://dx.doi.org/10.1039/C2RA20646C
[8]	C. H. Huang and T. M. Chen, “Novel Yellow-emitting Sr8MgLn(PO4)7:Eu2+ (Ln = Y, La) Phosphors for Applications in White LEDs with Excellent Color Rendering Index,” Inorganic Chemistry, Vol. 50, No. 12, 2011, pp. 5725-5730.
[9]	Z. Wu, M. Gong, J. Shi, G. Wang and Q. Su, “Dibarium Magnesium Diphosphate Yellow Phosphor Applied in InGaN-Based LEDs,” Chemistry Letters, Vol. 36, No. 3, 2007, pp. 410-411. http://dx.doi.org/10.1246/cl.2007.410
[10]	D. Deng, H. Yu, Y. Li, Y. Hua, G. Jia, S. Zhao,H. Wang, L. Huang, Y. Li, C. Lia and S. Xu, “Ca4(PO4)2O:Eu2+ Red-Emitting Phosphor for Solid-State Lighting: Structure, Luminescent Properties and White Light Emitting Diode Application,” Journal of Materials Chemistry C, Vol. 1, No. 19, 2013, pp. 3194-3199. http://dx.doi.org/10.1039/C3TC30148F
[11]	N. Yamatani, V. Petrykin, and M. Kakihana, “Synthesis of K3Ta3B2O12 Photocatalytic Material by Aqueous Solution-Based Process Using a Novel Water Soluble Tantalum Complex,” Journal of the Ceramic Society of Japan, Vol. 117, No. 1363, 2009, pp. 308-312.
[12]	J. Pretula and J. Polyn, “Formation of Poly(ethylene phosphates) in Polycondensation of H3PO4 with Ethylene glycol. Kinetic and Mechanistic Study,” Journal of Polymer Science Part A: Polymer Chemistry, Vol. 46, No. 3, 2008, pp. 830-843. http://dx.doi.org/10.1002/pola.22427
[13]	M. Vlasse, P. Bochu, C. Parent, J. P. Chaminade, A. Daoudi, G. Le Flem and P. Hagenmuller, “Structure Determination of Calcium Neodymium Potassium Double Phosphate CaKNd(PO4)2,” Acta Crystallographica Section B: Structural Science, Vol. 38, No. 9, 1982, pp. 2328-2331. http://dx.doi.org/10.1107/S0567740882008735
[14]	A. Oki, M. Zeller, Y. Coranza, J. Luevano and A. D. Hunter, “Hydrothermal Synthesis and Structure of an Openframework Co0.7Zn1.3(PO4)2(NH3-CH2 CH2NH3) and Co6.2(OH)4(PO4)4Zn1.80, a New Adamite Type Phase,” Inorganica Chimica Acta, Vol. 360, No. 9, 2007, pp. 2917-2922. http://dx.doi.org/10.1016/j.ica.2007.02.032