Aerosol-gel synthesis of ZnO quantum dots dispersed in SiO2 matrix and their characteristics

에어로솔-젤 법을 이용한 SiO2에 분산된 ZnO 양자점의 합성과 그 특성

  • Kim, Sang-Gyu (School of Mechanical Engineering, Pusan Clean Coal Center, Pusan National University) ;
  • Firmansyah, Dudi Adi (School of Mechanical Engineering, Pusan Clean Coal Center, Pusan National University) ;
  • Lee, Kwang-Sung (School of Mechanical Engineering, Pusan Clean Coal Center, Pusan National University) ;
  • Lee, Donggeun (School of Mechanical Engineering, Pusan Clean Coal Center, Pusan National University)
  • 김상규 (부산대학교 기계공학부) ;
  • ;
  • 이광승 (부산대학교 기계공학부) ;
  • 이동근 (부산대학교 기계공학부)
  • Received : 2010.03.02
  • Accepted : 2010.05.09
  • Published : 2010.06.30

Abstract

ZnO quantum dots embedded in a silica matrix without agglomeration were synthesized from $TEOS:Zn(NO_3)_2$ solutions in one-step process by aerosol-gel method. It was successfully demonstrated that the size of ZnO Q-dots could be controlled from 2 to 7 mm verified by a high resolution transmission electron microscope observation. The line scanning energy dispersive X-ray spectroscopy(EDS) revealed that the Q-dots existed preferentially inside SiO2 sphere when Zn/Si < 0.5. However, the Q-dots distributed homogeneously all over the sphere when Zn/Si > 1.0. Blue-shifted UV/Vis absorption peak observation confirmed the quantum size effect on the optical properties. The photoluminescence(PL) emission peaks of the powders at room temperature were consistent with previous reports in the following aspects: 1) PL characteristics are dominated by two peaks of deep-level defect-related emissions at 2.4 - 2.8 eV, 2) the first defect-related peak at 2.4 eV was blue shifted due to the quantum size effect with decreasing the concentration of $Zn(NO_3)_2$(decreasing the size of ZnO q dots). More interestingly, the existence of surface-exposed ZnO q dots affects greatly the second defect PL peak at 2.8 eV.

Keywords

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