Photoluminescence of willemite ($Zn_2SiO_4$ : Mn) phosphors prepared by the MOD process

MOD법에 의해 합성한 Willemite($Zn_2SiO_4$:Mn) 형광체의 발광 특성

  • Lee, Byeong-Woo (Department of Materials Engineering, Korea Maritime University) ;
  • Lee, Seon-Gil (Department of Materials Engineering, Korea Maritime University) ;
  • Cho, Hyun (Department of Nanosystem and Nanoprocess Engineering, Pusan National University)
  • 이병우 (한국해양대학교 재료공학과) ;
  • 이선길 (한국해양대학교 재료공학과) ;
  • 조현 (부산대학교 나노시스템공정공학과)
  • Published : 2007.04.30

Abstract

Willemite green phosphor powders have been prepared by the metallo-organic decomposition (MOD) method, and the photoluminescence and phase formation were studied as a function of both the firing temperature ($800{\sim}1100^{\circ}C$) and the concentration of Mn activator ($4{\sim}12 mol%$). Under 254 nm excitation source, the emission intensity of the phosphors increased with increasing the firing temperature from 800 to $1000^{\circ}C$. From the XRD analysis, the powders heat-treated above $1000^{\circ}C$ showed willemite crystal structure. The maximum emission intensity was obtained far the phosphors heat-treated at $1000^{\circ}C$ with 8 mol% of Mn content. The concentration quenching was occurred when the Mn concentration exceeded 10 mol%. The phosphor particles showed spherical shapes with the average size of $0.4{\sim}0.5{\mu}m$ by the SEM morphology.

Metallo-organic decomposition(MOD)법으로 willemite 녹색 형광체를 합성하였고, 열처리 온도($800{\sim}1100^{\circ}C$) 및 Mn 활성제 농도($4{\sim}12 mol%$)에 따른 발광특성과 상합성에 대해 조사하였다. 254nm 여기원을 사용한 측정에서 형광체의 열처리 온도가 $800^{\circ}C$에서 $1000^{\circ}C$로 증가함에 따라 상대 발광 피크강도는 크게 증가하였고, XRD 분석 결과 $1000^{\circ}C$ 이상의 열처리 온도에서 전형적인 willemite 결정 구조를 보여 주었다. $1000^{\circ}C$의 온도로 열처리한 willemite 형광체는 Mn 활성제 농도가 8mol% 일 때 최대 발광 강도를 나타내었으며 10mol% 이상에서는 발광 강도가 급격히 저하되는 농도 ??칭 현상이 관찰되었다. SEM 분석 결과 형광체 입자 형상은 구형에 가까웠으며 $1000^{\circ}C$에서 소성된 형광체 입자 크기는 약 $0.4{\sim}0.5{\mu}m$ 이었다.

Keywords

References

  1. E. Cvalli, A. Belletti and E. Zannoni, 'Luminescence of Fe-doped willemite single crystals', J. Solid State Chem. 117 (1995) 16 https://doi.org/10.1006/jssc.1995.1240
  2. C.R. Ronda and T. Amrein, 'Evidence for exchangeinduced luminescence in $Zn_{2}SiO_{4}$: Mn', J. Luminescence 69 (1996) 245 https://doi.org/10.1016/S0022-2313(96)00103-2
  3. A.M. Pires and M.R. Davolos, 'Luminescence of europium(III) and manganese(II) in barium and zinc orthosilicate', Chemistry of Materials 13 (2001) 21 https://doi.org/10.1021/cm000063g
  4. B.H. Cho, K.S. Sohn, H.D. Park, H.MJ. Chang and T.S. Hwang, 'Photoluminescence properties of $Zn_{2-x-y}SiO_{4}:Mn_{x},M_{y}$ Phosphors', J. Kor. Chem. Soc. 43 (1999) 206
  5. D.J. Robbins, N.S. Casewell, E.A. Avouris, E.A. Giess, I.F. Chang and D.B. Dove, 'A diffusion model for electron-hole recombination in $Zn_{2}SiO_{4}}$: (Mn,As) phosphors', J. Electrochem. Soc. 132 (1985) 2784 https://doi.org/10.1149/1.2113665
  6. C.S. Jang, K.K. Orr and C.K. Lee, 'The study of photoluminescence on Willemite phosphor', J. Kor. Ceramic Soc. 21 (1984) 245
  7. A. Morell and N. El Khiati, 'Green phosphors for large plasma TV screens', J. Electrochem. Soc. 140 (1993) 2019 https://doi.org/10.1149/1.2220755
  8. E.S. Park, H.J. Chang and T.H. Cho, 'Photoluminescent properties of $Zn_{2}SiO_{4}$ : Mn green phosphors prepared by the solution reaction method', Kor. J. Materials Res. 9 (1999) 46
  9. H.X. Zhang, C.H. Kam, Y. Zhou, X.Q. Han, S. Buddhudu, YL. Lam and C.Y. Chan, 'Deposition and photoluminescence of sol-gel derived $Tb^{3+}:Zn_{2}SiO_{4}$ films on $SiO_{2}/Si$', Thin Solid Films 370 (2000) 50 https://doi.org/10.1016/S0040-6090(00)00948-2
  10. C. Yoon and S. Kang, 'Synthesis of $Zn_{2-x}Mn_{x}SiO_{4}$ phosphors using a hydrothermal technique', J. Materials Res. 16 (2001) 1210
  11. K.S. Sohn, B. Cho and H.D. Park, 'Photoluminescence behavior of manganese-doped zinc silicate phosphors', J. Amer. Ceramic Soc. 82 (1999) 2779 https://doi.org/10.1111/j.1151-2916.1999.tb02155.x