활성제 이온의 농도 변화에 따른 La2MoO6:RE3+ (RE = Eu, Sm) 형광체의 발광 특성
Luminescence Properties of La2MoO6:RE3+ (RE = Eu, Sm) Phosphors Subjected to the Different Concentrations of Activator Ions
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Eu3+- or Sm3+-doped La2MoO6 phosphors were synthesized with different concentrations of activator ions via a solid-state reaction. The X-ray diffraction patterns exhibited that crystalline structures of all the phosphors were tetragonal systems with the dominant peak occurring at (103) plane, irrespective of the concentration and the type of activator ions. The crystallites showed the pebble-like crystalline shapes and the average crystallite size increased with a tendency to agglomerate as the concentration of Eu3+ ions increased. The excitation spectra of Eu3+-doped La2MoO6 phosphors contained an intense charge transfer band centered at 331 nm in the range of 250-370 nm and three weak peaks at 381, 394, and 415 nm, respectively, due to the 7F0→5L7, 7F0→5L6, and 7F0→5D3 transitions of Eu3+ ions. The emission spectra under excitation at 331 nm exhibited a strong red band centered at 620 nm and two weak bands at 593 and 704 nm. As the concentration of Eu3+ increased from 1 to 20 mol%, the intensities of all the emission bands gradually increased. For the Sm3+-doped La2MoO6 phosphors, the emission spectra consisted of an intense emission band at 607 nm arising from the 4G5/2→6H7/2 transition and three relatively small bands at 565, 648, and 707 nm originating from the 4G5/2→6H5/2, 4G5/2→6H9/2, and 4G5/2→6H11/2 transitions of Sm3+, respectively. The intensities of all the emission bands approached maxima when concentration of Sm3+ ions was 5 mol%. These results indicate that the optimum concentrations for highly-luminescent red and orange emission are 20 mol% of Eu3+ and 5 mol% of Sm3+ ions, respectively.
Abstract
Eu3+- or Sm3+-doped La2MoO6 phosphors were synthesized with different concentrations of activator ions via a solid-state reaction. The X-ray diffraction patterns exhibited that crystalline structures of all the phosphors were tetragonal systems with the dominant peak occurring at (103) plane, irrespective of the concentration and the type of activator ions. The crystallites showed the pebble-like crystalline shapes and the average crystallite size increased with a tendency to agglomerate as the concentration of Eu3+ ions increased. The excitation spectra of Eu3+-doped La2MoO6 phosphors contained an intense charge transfer band centered at 331 nm in the range of 250-370 nm and three weak peaks at 381, 394, and 415 nm, respectively, due to the 7F0→5L7, 7F0→5L6, and 7F0→5D3 transitions of Eu3+ ions. The emission spectra under excitation at 331 nm exhibited a strong red band centered at 620 nm and two weak bands at 593 and 704 nm. As the concentration of Eu3+ increased from 1 to 20 mol%, the intensities of all the emission bands gradually increased. For the Sm3+-doped La2MoO6 phosphors, the emission spectra consisted of an intense emission band at 607 nm arising from the 4G5/2→6H7/2 transition and three relatively small bands at 565, 648, and 707 nm originating from the 4G5/2→6H5/2, 4G5/2→6H9/2, and 4G5/2→6H11/2 transitions of Sm3+, respectively. The intensities of all the emission bands approached maxima when concentration of Sm3+ ions was 5 mol%. These results indicate that the optimum concentrations for highly-luminescent red and orange emission are 20 mol% of Eu3+ and 5 mol% of Sm3+ ions, respectively.
참고문헌 (20)
- 오명진, "Development and Characterization of Ln3+-doped Gd2GeO5 Phosphors", Journal of the Korean Physical Society, 63(7), pp.1427~1431 (2013), 한국물리학회
- N. Niu, "Solvothermal Synthesis of SrMoO4:Ln (Ln=Eu3+, Tb3+, Dy3+) nanoparticles and Its Photoluminescence Properties at Room Temperature", Mater. Res. Bull, 46, pp.333~339 (2011)
- M. Nazarov, "Rare Earth Double Activated Phosphors for Different Applications", J. Rare Earth, 28, pp.1~11 (2010)
- F. Meng, "Synthesis and Spectral Characteristics of La2MoO6:Ln3+(Ln=Eu, Sm, Dy, Pr, Tb) Polycrystals", J. Rare Earth, 30(9), pp.866~870 (2012)
- C. C. Lin, "KBaPO4:Ln (Ln=Eu, Tb, Sm) Phosphors for UV Excitable White Light-Emitting Diodes", J. Lumin, 129, pp.1682~1684 (2009)
- Y. C. Li, "Synthesis and Luminescent Properties of Ln3+ (Eu3+, Sm3+, Dy3+)-doped Lanthanum Aluminum Germanate LaAlGe2O7 Phosphors", J. Alloy. Compd, 439, pp.367~375 (2007)
- R. Yadav, "Intense Red-emitting Y4Al2O9:Eu3+ Phosphor with Short Decay Time and High Color Purity for Advanced Plasma Display Panel", Opt. Express, 17(24), pp.22023~22030 (2009)
- F. Bi, "Electrospinning Preparation and Photoluminescence Properties of Y3Al5O12:Eu3+ Nanobelts", Mater. Res, 18(2), pp.411~416 (2015)
- Z. Yang, "Synthesis and Luminescence Properties of a novel red Sr3Bi(PO4)3:Sm3+ Phosphor", J. Rare Earth, 30(12), pp.1199~1202 (2012)
- 김준한, "Dy3+와 Eu3+ 이온이 동시 도핑된 CaMoO4 형광체의 합성과 발광 특성", 한국표면공학회지, 48(3), pp.82~86 (2015), 한국표면공학회[DOI]
- S. Kaur, "Spectroscopic and Photoluminescence Characteristics of Sm3+doped Calcium Aluminozincate Phosphor for Applications in w-LED", Ceram. Int, 43, pp.7401~7407 (2017)
- S. Cho, "Synthesis and Luminescence Properties of LaVO4:RE3+ (RE=Sm, Eu, Tb, Tm) Phosphors", J. Nanosci. Nanotechno, 13(11), pp.7546~7550 (2013)
- P. L. Li, "Luminescence Characteristics of Eu3+ Activated Borate Phosphor for White Light Emitting Diode", Chinese Phys. B, 17(5), pp.1907~1910 (2008)
- S. Shi, "Effects of Charge Compensation on the Luminescence Behavior of Eu3+ Activated CaWO4 Phosphor", Opt. Mater, 30, pp.1616~1620 (2008)
- Y. Tao, "EXAFS Studies of Luminescence Centres in Eu3+ Doped Nanoscale Phosphors", Mater Lett, 28, pp.137~140 (1996)
- G. S. R. Raju, "Photouminescence and Cathodoluminescence Properties of Nanocrystalline Ca2Gd8Si6O26:Sm3+Phosphors", J. Am. Ceram. Soc, 95(1), pp.238~242 (2012)
- Sk. Mahamuda, "Spectral Characterisation of Sm3+ ions doped Oxyfluoroborate Glasses for Visible Orange Luminescent Applications", J. Lumin, 154, pp.410~424 (2014)
- X. Xiao, "Synthesis and Luminescence Properties of YVO4:Eu3+ Cobblestone-like microcrystalline Phosphors Obtained from the Mixed Solvent-Thermal Method", Mater. Sci. Eng. B, 176, pp.72~78 (2011)
- B. J. Chen, "Sm3+-doped Germanate Glass Channel Waveguide as Light Source for Minimally Invasive Photodynamic Therapy Surgery", Opt. Express, 20(2), pp.879~889 (2012)
- B. Tian, "Concentration and Temperature Quenching Mechanisms of Dy3+Luminescence in BaGd2ZnO5 Phosphors", J. Phys. Chem. Solids, 73, pp.1314~1319 (2012)