Fluorescence Properties of Eu³⁺ Doped in Na₅Lu₉F₃₂ Single Crystals

Abstract

Eu³⁺ ion doped cubic Na₅Lu₉F₃₂ single crystals with high quality were synthesized by a modified Bridgman method by using a high 70–90 °C/cm temperature gradient for cross solid-liquid interface. The optical spectroscopic investigations of the obtained single crystal were reported for the absorption, excitation and emission. The experimental results show that a strong red emission at 609 nm attributing to the ⁵D₀→⁷F₂ transition of Eu³⁺ doped Na₅Lu₉F₃₂ single crystals can be obtained under the excitation of 394 nm light and reach the maximum when the Eu³⁺ doping concentration is 4mol% in present research. The local covalent is enhanced and symmetry is reduced with the increase of Eu³⁺ concentrations inferring from the strength parameters Ω ₂ and Ω ₄ calculated by their measured emission spectra. The CIE chromaticity coordinates of the 4mol% Eu³⁺ doped Na₅Lu₉F₃₂ single crystals are calculated as (x=0.626, y=0.3736), which are close to the NTSC standard values for red (x=0.67, y=0.33). The experimental results reveal that the single crystal can be used as potential red phosphors under near ultraviolet (NUV) light excitation.

Keywords

optical materials / crystal growth / red phosphors / rare earth

References

[1] Ronda CR, Jüstel T, Nikol H. Rare Earth Phosphors: Fundamentals And Applications[J]. Journal of Alloys Compounds, 1998, 275–277: 669-676.

[2] Du HY, Lan YJ, Xia Z B, et al. Upconversion Luminescence of Yb3+/Ho3+/Er3+/Tm3+ Co–doped KGd(WO4)2 Powders[J]. Journal of Rare Earths, 2010, 28: 697-700.

[3] Wei DL, Huang YL, Shi L, et al. Up–conversion Luminescence from Nd3+ Ions Doped in NaBi(WO4)2 Single Crystal[J]. Journal of Rare Earths, 2009, 27: 905-910.

[4] Li J, Wang JY, Han SJ, et al. Growth, Structural, Thermal PropertiesAand Spectroscopic Characteristics of KTb(WO4)2 Single Crystal[J]. Journal of Rare Earths, 2012, 30: 967-971.

[5] Hu Y. Preparation. Luminescent Properties of (Ca1–x, Srx)S: Eu2+ Red–emitting Phospher for White LED[J]. Journal of Luminescence, 2005, 111: 139-145.

[6] Setlur AA, Heward WJ, Gao Y, et al. Crystal Chemistry and Luminescence of Ce3+–Doped Lu2CaMg2(Si,Ge)3O12 and Its Use in LED Based Lighting[J]. Chemistry of Materials, 2006, 18: 3 314-3 322.

[7] Kang M, Yin GF, Liu J, et al. Synthesis and Luminescence Properties of Red Phosphor CaO: Eu3+[J]. Journal of Wuhan University of Technology–Mater. Sci. Ed., 2009, 24: 20-24.

[8] Sharma KG, Singh NR. Synthesis of CaWO4: Eu3+ Phosphor Powders Via Ethylene Glycol Route and Its Optical Properties[J]. Journal of Rare Earths, 2012, 30: 310-314.

[9] Zhang Q, Meng QY, Tian Y, et al. Luminescent Properties of Eu3+ Doped Gd2WO6 and Gd2(WO4)3 Nanophosphors Prepared Via Co–precipitation Method[J]. Journal of Rare Earths, 2011, 29: 815-821.

[10] Lukowiak A, Wiglusz JR, Pazik R, et al. Synthesis, Structure and Luminescence Properties of KEu0.01Gd0.19Yb0.8(WO4)2 Powder[J]. Journal of Rare Earths, 2009, 27: 564-568.

[11] Kodaira CA, Brito HF, Felinto MCFC. Luminescence Investigation of Eu3+ Ion in the RE2(WO4)3 Matrix (RE=La and Gd) Produced Using the Pechini Method[J]. Journal of Solid State Chem, 2003, 171: 401-407.

[12] Kodaira CA, Brito HF, Malta OL, et al. Luminescence and Energy Ttransfer of the Europium (III) Tungstate Obtained Via the Pechini Method[J]. Journal of Luminescence, 2003, 101: 11-21.

[13] Yang JY, Su YC, Chen Z, et al. Hydrothermal Synthesis and Characterization of Nanocrystalline Gd2Sn2O7: Eu3+ Phosphors[J]. Advanced Materials Research, 2011, 239–242: 851-2 854.

[14] Zhao XX, Wang XJ, Chen BJ, et al. Novel Eu3+–doped Red–emitting Phosphor Gd2Mo3O9 for White–light–emitting–diodes (WLEDs) Application[ J]. Journal of Alloys and Compounds, 2007, 433: 352-355.

[15] Dubey V, Kaur J, Agrawal S. Effect of Europium Concentration on Photoluminescence and Thermoluminescence Behavior of Y2O3: Eu3+ Phosphor[J]. Superlattices & Microstructures, 2014, 67: 156-171.

[16] Pollnau M, Gamelin DR, Lüthi SR, et al. Power Dependence of Upconversion Luminescence in Lanthanide and Transition–metal–ion Systems[ J]. Physical Review B, 2000, 61: 3 337-3 346.

[17] Jiang YZ, Xia HP, Zhang JZ, et al. Growth and Optical Spectra of Tb3+/Eu3+ Co–doped Cubic NaYF4 Single Crystal for White Light Emitting Diode[J]. Journal of Materials Science & Technology, 2015, 31: 1 232-1 236.

[18] Jiang DS, Xia HP, Zhang J, et al. Luminescent Properties of Eu3+–doped α–NaYF4 Single Crystal under NUV–excitation[J]. Journal of Modern Optics, 2017, 64: 164-169.

[19] Thoma RE, Insley H, Hebert GM. The Sodium Fluoride–lanthanide Trifluoride Systems[J]. Inorganic Chemistry, 1966, 5: 1 222-1 229.

[20] Lv RC, Yang PP, Dai YL, et al. Lutecium Fluoride Hollow Mesoporous Spheres with Enhanced UC Luminescent Bio–imaging and Light–triggered Drug Release by Gold Nanocrystals[J]. Acs Applied Materials & Interfaces, 2014, 6: 15 550-15 563.

[21] Shmyt’ko IM, Strukova GK. Fine Sructure of Na5Lu9F32 Nanocrystallites Formed at the Initial Stages of Crystallization[J]. Physics of the Solid State, 2009, 51: 1 907-1 911.

[22] Feng ZG, Xia HP, Wang C, et al. Fluorescence Spectra of Na5Lu9F32 Single Crystals Co–doped with Ho3+/Tm3+ Grown by Bridgman Method[J]. Chemical Physics Letters, 2016, 652: 68-72.

[23] Wang C, Xia HP, Feng ZG, et al. Infrared Luminescent Properties of Na5Lu9F32 Single Crystals Co–doped Er3+/Yb3+ Grown by Bridgman Method[J]. Journal of Alloys and Compounds, 2016, 686: 816-822.

[24] Ghosh P, Patra A. Influence of Crystal Phase and Excitation Wavelength on Luminescence Properties of Eu3+–Doped Sodium Yttrium Fluoride Nanocrystals[J]. Journal of Physical Chemistry C, 2008, 112: 19 283-19 292.

[25] Ghosh P, Patra A. Tuning of Crystal Phase and Luminescence Properties of Eu3+ Doped Sodium Yttrium Fluoride Nanocrystals[J]. Journal of Physical Chemistry C, 2008, 112: 3 223-3 231.

[26] Wang JW, Song H, Kong X, et al. Fluorescence Properties of Trivalent Europium Doped in Various Niobate Codoped Glasses[J]. Journal of Applied Physics, 2003, 93: 1 482-1 486.

[27] Hu J, Xia HP, Hu HY, et al. Sythesis and Efficient Near–infrrared Quantum Cutting of Pr/Yb Co–doped LiYF Single Crystals[J]. Journal of Applied Physics, 2012, 112: 073 518.

[28] Ofelt GS. Intensities of Crystal Spectra of Rare–Earth Ions[J]. The Journal of Chemical Physics, 1962, 37: 511-520.

[29] Han J, Mo ZJ, Zhang XS, et al. Luminescent Properties of Eu3+–doped Glass Ceramics Containing BaCl2 Nanocrystals under NUV Excitation for White LED[J]. Journal of Luminescence, 2016, 175: 187-192.