Direct white-light from core-shell-like sphere with Sr₃Mg-Si₂O₈: Eu²⁺, Mn²⁺ coated on Sr₂SiO₄:Eu²⁺

Abstract

A method of color mixture for white light is presented with Sr₃MgSi₂O₈:Eu²⁺, Mn²⁺ shell coated on Sr₂SiO₄:Eu²⁺ core by spray pyrolysis procedure. Upon near ultraviolet (NUV) excitation, a 550 nm band emission of Eu²⁺ from core host combines with the simultaneous emissions of Eu²⁺ at 457 nm and Mn²⁺ at 683 nm based on energy transfer in the shell lattice to generate warm white light with color rendering index (CRI) of 91. With such a core-shell-like structure, the re-absorption of blue light from shell layer can be effectively suppressed, and the chemical stability of the phosphor is verified experimentally to be superior to that of the Sr₂SiO₄:Eu²⁺. This new proposed phosphor provides great potential in the color mixture of blending-free phosphor converted white NUV light emitting diode (LED) devices.

Keywords

Light Emit Diode / Correlate Color Temperature / Color Render Index / Color Mixture / Shell Lattice

References

[1] ZhouL-z, LiuH, AnB, WuF-s, WuY-p. Jounal of Optoelectronics·Laser, 2010, 21: 175

[2] TonzaniS. Nature, 2009, 459: 312

[3] RohH-S, KimD H, ParkI-J, SongH J, HurS, KimD-W, HongK S. Journal of Materials Chemistry, 2012, 22: 12275

[4] JangH S, ImW B, LeeD C, JeonD Y, KimS S. Journal of Luminescence, 2007, 126: 371

[5] BachmannV, RondaC, MeijerinkA. Chemistry of Materials, 2009, 21: 2077

[6] SatoY, TakahashiN, SatoS. Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers, 1996, 35: L838

[7] KuoT-W, LiuW-R, ChenT-M. Optics Express, 2010, 18: 1888

[8] FuhrmannD, RetzlaffT, RossowU, BremersH, HangleiterA, AdeG, HinzeP. Appl. Phys. Lett., 2006, 88: 191108

[9] YimS S, LeeM S, KimK S, KimK B. Appl. Phys. Lett., 2006, 89: 093115

[10] YangW J, ChenT M. Appl. Phys. Lett., 2006, 88: 101903

[11] JeongJ, JayasimhadriM, LeeH S, JangK W, YiS S, JeongJ H, KimC. Physica B-Condensed Matter, 2009, 404: 2016

[12] LiuY, ZhangX, HaoZ, WangX, ZhangJ. Chemical Communications, 2011, 47: 10677

[13] MaL, WangD-J, MaoZ-Y, LuQ-F, YuanZ-H. Appl. Phys. Lett., 2008, 93: 144101

[14] KorthoutK, SmetP F, PoelmanD. Appl. Phys. Lett., 2011, 98: 261919

[15] MaoZ-Y, ZhuY-C, GanL, ZengY, XuF-F, WangY, TianH, WangD-J. Journal of Materials Chemistry, 2012, 22: 19839

[16] MaoZ Y, ZhuY C, GanL, XuF F, WangY, WangD J. Journal of Materials Chemistry, 2012, 22: 824

[17] BarryT L. J. Electrochem. Soc.: Solid State Science, 1968, 115: 733

[18] BlasseG, WanmakerW L. Philips Res. Repts., 1968, 23: 189

[19] LiuL-Y, WangD-J, MaoZ-Y, LiuY-H, LiX-Z, LuQ-F. Optoelectronics Letters, 2009, 5: 26

[20] KimJ S, JeonP E, ChoiJ C, ParkH L, MhoS I, KimG C. Appl. Phys. Lett., 2004, 84: 2931

[21] KimJ S, JeonP E, ParkY H, ChoiJ C, ParkH L. J. Electrochem. Soc., 2005, 152: H29

[22] WangP, SongJ, TianH, LuQ-F, WangD-J. Optoelectronics Letters, 2012, 8: 201

This work has been supported by the National Natural Science Foundation of China (Nos.21076161, 50802062 and 50872091).