Preparation of $Ga_2O_3:Eu^{3+}$ phosphors by homogeneous precipitation

균일침전법에 의한 $Ga_2O_3:Eu^{3+}$ 형광체의 제조

  • 천민호 (한밭대학교 신소재공학부) ;
  • 박인용 (한밭대학교 신소재공학부) ;
  • 이종원 (한밭대학교 신소재공학부) ;
  • 김선태 (한밭대학교 신소재공학부)
  • Published : 2002.06.01

Abstract

Europium-activated $Ga_2O_3$ phosphor powders were prepared by homogeneous precipitation method. The resulting powders were characterized by means of TG/DTA, XRD, FT-IR and SEM, Two kinds of powders formed were the crystalline GaOOH and the amorphous-like $\gamma$-$Ga_2O_3$ phases. When the urea concentration was below 0,5 M, rod-like micrometer-sized GaOOH powders were formed. They were transformed via $\alpha$-$Ga_2O_3$ to $\beta$-$Ga_2O_3$ phases under heat treatment. On the other hand, the nanometer-sized $\gamma$-$Ga_2O_3$ powders were formed with urea concentrations higher than 1.0 M, and they were directly changed into $\beta$-$Ga_2O_3$.Photoluminescence (PL) spectra were observed at room temperature, and PL intensities of nanometer-sized $Ga_2O_3$ : $Eu^{3+}$ powders around 610 nm were higher than those of micrometer-sized ones.

$Ga_2O_3$ : $Eu^{3+}$ 형광체 분말을 균일침전법에 의해 제조하여 TG/DTA, XRD, FT-IR, SEM 등으로 특성을 분석하였다. 결정질 GaOOH 와 비정질에 가까운 $\gamma$-$Ga_2O_3$ 등 두 종류의 분말이 얻어졌다. 요소 농노가 0.5 M 이하에서는 입자는 막대모양을 이루고, 열처리에 따라 $\alpha$-$Ga_2O_3$을 거쳐서 $\beta$-$Ga_2O_3$상으로 변태하였다. 한편 나노미터 크기를 갖는 $\gamma$-$Ga_2O_3$분말은 1.0 M 이상의 요소 농도에서 생성되며, 직접 $\beta$-$Ga_2O_3$으로 전이하였다. 실온에서 광 발광 특성을 비교한 결과 마이크로미터 크기의 분말에 비해 나노미터 크기의 분말이 610 nm에서의 발광 강도가 더 크게 나타났다.

Keywords

References

  1. P.D. Rack and P.H. Holloway, 'Structure, Device Phys-ics, and Material Properties of Thin Film Electrolumi-nescent Displays', Mater. Sci. Eng. R21 (1998) 171
  2. S.S. Kim et al., 'Display Engineering I & II' (Chung-bum, 2000)
  3. T. Minami, T. Miyata and Y. Sakagami, 'TFEL Devices Using Oxide Thin Films without Vacuum Process', Sur-face and Coating Tech. 108 (1998) 594
  4. T. Xiao et al., 'Thin Film Electroluminescence in Highly Anisotropic Oxide Materials', Appl. Phys. Lett. 72 (1998) 3356
  5. T. Minami et al., 'Electroluminescent Devices with $Ga_2O_3$: Mn Thin-Film Emitting Layer', Jpn. J. Appl. Phys. 39 (2000) L524
  6. T. Miyata, T. Nakatani and T. Minami, 'Gallium Oxide as Host Material for Multicolor Emitting Phosphors', J. Lumin. 87 (2000) 1183
  7. T. Miyata, T. Nakatani and T. Minami, 'Manganese-Activated Gallium Oxide Electroluminescent Phosphor Thin Films Prepared Using Various Deposition Meth-ods', Thin Solid Films 373 (2000) 145
  8. H.H. Tippins, 'Optical Absorption and Photoconductiv-ity in the Band Edge of $\beta$-$Ga_2O_3$' Phys. Rev. 140(1A) (1965) A316
  9. R. Roy, VG. Hill and E.F. Osborn, 'Polymorphism of $Ga_2O_3$and the System $Ga_2O_3-H_2O$', J. Am. Chem. Soc. 74 (1952) 719
  10. T. Sato and T. Nakamura, 'Thermal Decomposition of Gallium Hydroxides', Thermochim. Acta 53 (1982) 281
  11. S. Hamada, K. Bando and Y Kudo, 'Formation of Monodispersed Gallium Hydrous Oxide Particles by Hydrolysis at Elevated Temperatures', Nippon Kagaku Kaishi (6) (1984) 1068
  12. S. Avivi et al., 'Sonochemical Hydrolysis of Ga$^{3+}$ Ions: Synthesis of Scroll-like Cylindrical Nanoparticles of Gallium Oxide Hydroxide', J. Am. Chem. Soc. 121 (1999) 4196
  13. H. Ryu and H.D. Park, 'Luminescence Properties of Dy$^{3+}$- (or Tm$^{3+}$) Doped $Ga_2O_3$ and Zn$Ga_2O_4$ Phos- phors', Kor. J. Ceram. 3 (1997) 134
  14. G.A. Hirata, F. Ramos, R. Garcia, E.J. Bosze, J. McKit-trick and F. A. Ponce, 'A New Combustion Synthesis Method for GaN:$^{3+}$ and $Ga_2O_3$ : Eu$^{3+}$ Luminescent Powders', Phys. Stat. Sol. (A) 188 (2001) 179
  15. X.C. Wu et al., 'Crystalline Gallium Oxide Nanowires: Intensive Blue Light Emitters', Chem. Phys. Lett. 328 (2000).5 https://doi.org/10.1016/S0009-2614(00)00899-X
  16. G.S. Park et al., 'Structural Investigation of Gallium Oxide ($\beta$-$Ga_2O_3$) Nanowires Grown by Arc-Discharge', J. Crystal Growth 220 (2000) 494
  17. H.Z. Zhang et al., '$Ga_2O_3$ Nanowires Prepared by Phy-sical Evaporation', Solid State Commun. 109 (1999) 677
  18. WQ. Han et al., 'Growth and Microstructure of$Ga_2O_3$ Nanorods', Solid State Commun. 115 (2000) 527
  19. B. Aiken, WP. Hsu and E. Matijevic, 'Preparation and Properties of Monodispersed Colloidal Particles of Lanthanide Compounds: III, Yttrium(III) and Mixed Yttrium(III)/Cerium(III) Systems', J. Am. Ceram. Soc. 71 (1988) 845
  20. D.J. Sordelet and M. Akinc, 'Sintering of Monosized, Spherical Yttria Powders', J. Am. Ceram. Soc. 71 (1988) 1148
  21. D. Sordelet and M. Akinc, 'Preparation of Spherical, Monosized $Y_2O_3$ Precursor Particles', J. Colloid & Interface Sci. 122 (1988) 47
  22. C.O. Arean et al., 'Preparation and Characterization of Mesoporous $\gamma$-$Ga_2O_3$, Microporous Mesoporous Mater. 40 (2000) 35
  23. J. Silver et al., 'The Effect of Particle Morphology and Crystallite Size on the Upconversion Luminescence Properties of Erbium and Ytterbium Co-doped Yttrium Oxide Phosphors', J. Phys. Chem. B 105 (2001) 948
  24. S.M. Bradley, R.A. Kydd and R. Yamdagni, 'Detection of a New Polymeric Species Formed through the Hydrolysis of Gallium(III) Salt Solutions', J. Chem. Soc. Dalton Trans. (1990) 413
  25. L. Song and M. Rongjun, 'Synthesis and Structure of Hydrated Europium Carbonate', J. Cryst. Growth 169 (1996) 190
  26. W. Runde, C. Van Pelt and P.G. Allen, 'Spectroscopic Characterization of Trivalent f-Element (Eu, Am) Solid Carbonates', J. Alloys Camp. 303 (2000) 182
  27. G. Wakefield et al., 'Synthesis and Properties of Sub-50-nm Europium Oxide Nanoparticles', J. Colloid Inter-face Sci. 215 (1999) 179
  28. L. Binet and D. Gourier, 'Origin of the Blue Lumines-cence of $\beta$-$Ga_2O_3$' J. Phys. Chem. Solids 59 (1998) 1241
  29. T. Harwig and F. Kellendonk, 'Some Observations on the Photoluminescence of Doped $\beta$-Galliumsesquiox-ide', J. Solid State Chem. 24 (1978) 255