Potential red-emitting phosphor GdNbO₄:Eu³⁺,Bi³⁺ for near-UV white light emitting diodes

Abstract

A red-emitting phosphor GdNbO₄:Eu³⁺,Bi³⁺ was prepared by a high temperature solid-state reaction technique. The phosphor was characterized by X-ray diffraction (XRD), particle size analyzer and fluorescence spectrometer. The single phase of GdNbO₄:Eu³⁺,Bi³⁺ was obtained at 1150°C and the average particle diameter was about 2.30 μm. Excitation and emission spectra reveal that the phosphor can be efficiently excited by ultraviolet (UV) light (394 nm) and emit the strong red light of 612 nm due to the Eu³⁺ transition of ⁵D₀→⁷F₂. The optimum content of Eu³⁺ doped in the phosphor GdNbO₄:Eu³⁺ is 20mol%. The phosphor Gd_0.80NbO₄:0.20Eu³⁺,0.03Bi³⁺ shows much stronger photoluminescence intensity and better chromaticity coordinates (x=0.642, 0.352) than GdNbO₄:Eu³⁺. It is confirmed that Gd_0.80NbO₄:0.20Eu³⁺,0.03Bi³⁺ is a potential candidate for near-UV chip-based white light emitting diodes.

Keywords

phosphors / solid-state reactions / gadolinium niobate / light emitting diodes

References

[1] Narukawa Y., Sano M., Sakamoto T., Yamada T., Mukai T. Successful fabrication of white light emitting diodes by using extremely high external quantum efficiency blue chips. Phys. Status Solidi A, 2008, 205(5): 1081.

[2] Mueller A.H., Petruska M.A., Achermann M., Werder D.J., Akhadov E.A., Koleske D.D., Hoffbauer M.A., Klimov V.I. Multicolor light-emitting diodes based on semiconductor nanocrystals encapsulated in GaN charge injection layers. Nano Lett., 2005, 5(6): 1039.

[3] Cao F.B., Tian Y.W., Chen Y.J., Xiao L.J., Wu Q. Novel red phosphor for solid-state lighting: Ca_0.54Sr_0.34−1.5xEu_0.08-La_x(MoO₄)_y(WO₄)_1−y. J. Alloys Compd., 2009, 475(1–2): 387.

[4] Guo Y., Sun M., Guo W.M., Ren F.Q., Chen D.H. Luminescent properties of Eu³⁺ activated tungstate based novel red-emitting phosphors. Opt. Laser Technol., 2010, 42(8): 1328.

[5] Zhang Z.H., Huang Q., Zhao X., Huang Z.L. Enhanced red emission of CaMoO₄:Eu³⁺ phosphor by structural adjustment for white light-emitting diodes application. Phys. Status Solidi A, 2009, 206(12): 2839.

[6] Yi L.H., He X.P., Zhou L.Y., Gong F.Z., Wang R.F., Sun J.H. A potential red phosphor LiGd(MoO₄)₂:Eu³⁺ for light-emitting diode application. J. Lumin., 2010, 130(6): 1113.

[7] Haque Md.M., Kim D.K. Luminescent properties of Eu³⁺ activated MLa₂(MoO₄)₄ based (M=Ba, Sr and Ca) novel red-emitting phosphors. Mater. Lett., 2009, 63(9–10): 793.

[8] Sun X.Y., Zhang J.H., Zhang X., Lu S.Z., Wang X.J. A white light phosphor suitable for near ultraviolet excitation. J. Lumin., 2007, 122–123(1–2): 955.

[9] Yang Y.L., Li X.M., Feng W.L., Li W.L., Tao C.Y. Co-precipitation synthesis and photoluminescence properties of (Ca_1−x−y,Ln_y)MoO₄:xEu³⁺ (Ln = Y, Gd) red phosphors. J. Alloys Compd., 2010, 505(1): 239.

[10] Wang X.X., Wang J., Shi J.X., Su Q., Gong M.L. Intense red-emitting phosphors for LED solid-state lighting. Mater. Res. Bull., 2007, 42(9): 1669.

[11] Xiao X.Z., Yan B. Photoluminescence of Y_0.6Gd_0.4NbO₄: Eu³⁺/Tb³⁺ micrometric phosphors derived from hybrid precursors. Mater. Lett., 2007, 61(8–9): 1649.

[12] Huang J.L., Zhou L.Y., Liang Z.P., Gong F.Z., Han J.P., Wang R.F. Promising red phosphors LaNbO₄:Eu³⁺,Bi³⁺ for LED solid-state lighting application. J. Rare Earths, 2010, 28(3): 356.

[13] Xiao X.Z., Yan B. Synthesis and luminescent properties of novel RENbO₄:Ln³⁺ (RE=Y, Gd, Lu; Ln=Eu, Tb) micro-crystalline phosphors. J. Non Cryst. Solids, 2005, 351(46—48): 3634.

[14] Rao R.P. Preparation and characterization of fine-grain yttrium- based phosphors by sol-gel process. J. Electrochem. Soc., 1996, 143(1): 189.

[15] Guo C.F., Yang H.K., Fu Z.L., Li L., Choi B.C., Jeong J.H. A potential red-emitting phosphor BaGd₂(MoO₄)₄: Eu³⁺ for near-UV white LED. J. Am. Ceram. Soc., 2009, 92(8): 1713.

[16] Yi L.H., Zhou L.Y., Wang Z.L., Sun J.H., Gong F.Z., Wan W.P., Wang W. KGd(MoO₄)₂:Eu³⁺ as a promising red phosphor for light-emitting diode application. Curr. Appl. Phys., 2010, 10(1): 208.

[17] Zhang Y.M., Li Y.H., Li P., Hong G.Y., Yu Y.N. Preparation and upconversion luminescence of YVO₄:Er³⁺, Yb³⁺. Int. J. Miner. Metall. Mater., 2010, 17(2): 225.

[18] Wang Z.L., Liang H.B., Wang Q., Chen M.H., Gong M.L., Su Q. Novel red phosphor of Eu³⁺, Bi³⁺ coactivated double tungstates. Phys. Status Solidi A, 2009, 206(7): 1589.

[19] Park W.J., Jung M.K., Yoon D.H. Influence of Eu³⁺, Bi³⁺ co-doping content on photoluminescence of YVO₄ red phosphors induced by ultraviolet excitation. Sens. Actuators B, 2007, 126(1): 324.