標題: Efficient UV photoluminescence from monodispersed secondary ZnO colloidal spheres synthesized by sol-gel method
作者: Cheng, HM
Hsu, HC
Chen, SL
Wu, WT
Kao, CC
Lin, LJ
Hsieh, WF
光電工程學系
Department of Photonics
關鍵字: photoluminescence;sol-gel;nanomaterials;ZnO
公開日期: 15-四月-2005
摘要: ZnO colloidal spheres were synthesized by sol-gel method with a narrow size distribution. We controlled the size of the spheres during the secondary reaction with various amounts of primary reaction supernatant. The optimized condition of ZnO powders with an average diameter of 185 nm was obtained for structure analysis and study of optical properties. Transmission electron microscopy and X-ray diffraction reveal that the spheres are polycrystalline in the pure wurtzite phase. Markedly enhanced near-band-edge ultraviolet pbotoluminescence and significantly reduced defect-related visible emission were also observed. We attribute this observation to the localized bound excitons with high density of defect states. In addition, broad yellow emission and green emission were observed when the powders were post-annealed at 500 degrees C in air ambience. The origins of the defect-induced visible emissions are attributed to oxygen interstitials and oxygen vacancies. (c) 2005 Elsevier B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/j.jcrysgro.2004.12.133
http://hdl.handle.net/11536/13815
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2004.12.133
期刊: JOURNAL OF CRYSTAL GROWTH
Volume: 277
Issue: 1-4
起始頁: 192
結束頁: 199
顯示於類別:期刊論文


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