Photoluminescence Characteristics of Fine-sized Gd2O3:Eu Phosphor Powders Prepared by Spray Pyrolysis

분무열분해 공정에 의해 합성된 미세 Gd2O3:Eu 형광체의 발광 특성

  • Jung, Dae Soo (Department of Chemical Engineering, Konkuk University) ;
  • Koo, Hye Young (Department of Chemical Engineering, Konkuk University) ;
  • Lee, Sang Ho (Department of Chemical Engineering, Konkuk University) ;
  • Kang, Yun Chan (Department of Chemical Engineering, Konkuk University)
  • 정대수 (건국대학교 화학공학과) ;
  • 구혜영 (건국대학교 화학공학과) ;
  • 이상호 (건국대학교 화학공학과) ;
  • 강윤찬 (건국대학교 화학공학과)
  • Received : 2008.10.21
  • Accepted : 2008.12.01
  • Published : 2008.12.31

Abstract

Fine-sized $Gd_2O_3:Eu$ phosphor powders were prepared by post-treatment of the precursor powders with hollow shape obtained by spray pyrolysis from the spray solution with citric acid and flux material. Citric acid enabled the synthesis of fine-sized phosphor powders after post-treatment by increasing the hollowness of the precursor powders. The phosphor powders prepared from the spray solution without citric acid had several microns size. Flux materials increased the mean sizes of the phosphor powders. However, flux materials improved the photoluminescence intensities of the phosphor powders under ultraviolet. $Li_2CO_3$ as the flux material was appropriate to prepare the fine-sized $Gd_2O_3:Eu$ phosphor powders with high photoluminescence intensity. The phosphor powders below 3 wt% $Li_2CO_3$ of phosphor had submicron sizes after post-treatment temperatures of $1,050^{\circ}C$ and $1,150^{\circ}C$. The photoluminescence intensity of the phosphor powders post-treated at $1,150^{\circ}C$ was 124% of that of the phosphor powders post-treated at $1,050^{\circ}C$.

구연산 및 융제를 함유하는 분무용액으로부터 분무열분해법에 의해 속이 빈 전구체 분말들을 합성하고, 후열처리 과정을 거쳐 미세 $Gd_2O_3:Eu$ 형광체를 합성하였다. 구연산은 전구체 분말들의 다공성을 증대시킴으로써 후열처리 후에 미세 형광체 합성이 가능하게 하였다. 구연산을 첨가하지 않은 분무용액으로부터 합성된 형광체는 수 마이크론 크기를 가졌다. 융제는 형광체 분말의 크기와 자외선 하에서의 발광세기를 증대시켰다. 여러 가지 용제 중 휘도가 우수한 초미세 $Gd_2O_3:Eu$ 형광체 합성에는 $Li_2CO_3$가 적절하였다. $Li_2CO_3$ 융제의 첨가량이 형광체의 3 wt% 이하일 때 소성 온도 $1,050^{\circ}C$$1,050^{\circ}C$에서 합성된 형광체들은 서브마이크론 크기를 가졌다. 소성 온도 $1,050^{\circ}C$에서 얻어진 형광체의 발광 세기는 소성온도 $1,050^{\circ}C$에서 얻어진 형광체의 124%였다.

Keywords

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