Charge transfer bands of Mo-O and photoluminescence properties of micro-material Y₂MoO₆:Eu³⁺ red phosphor

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• 作者：Meifang Wang ; Hou Zhang ; Ling Li ; Xiaoguang Liu ; Fei Hong ; Rui Li ; Hejuan Song ; Meixi Gui ; Jinrui Shen ; Wenhao Zhu ; Jianbo Wang ; Liqun Zhou ; Jung Hyun Jeong
• 关键词：Photoluminescence ; Phosphors ; Eu3+ ; Charge transfer band ; Chemical bond parameter
• 刊名：Journal of Alloys and Compounds
• 出版年：5 February, 2014
• 年：2014
• 卷：585
• 期：Complete
• 页码：138-145
• 全文大小：2519 K

文摘

Eu³⁺ activated micrometer Y₂MoO₆ phosphors with strong red emission bands, under a broad-band excitation wavelength range of 340-400 nm, have been prepared by solid-state reaction and sol-gel technique. The photoluminescence indicates that the materials exhibit a characteristic red emission peak of Eu³⁺ ions at 612 nm. Compared with the material obtained by sol-gel method, the Y₂MoO₆:Eu prepared using solid state method showed much stronger red emission under the n-UV excitation. The broad excitation bands are assigned to charge transfer (CT) bands originating from the ligands (O) to the central ions Mo⁶⁺. About 12 nm shift of excitation bands in Y₂MoO₆:Eu was found. With a decrease of the crystalline size, the excitation bands of O-Mo CT shift to the short wavelength. The origin of CT shift in macromaterial Y₂MoO₆:Eu was investigated quantitatively from the chemical bond viewpoint. All constituent chemical bonds in the crystal with or without oxygen vacancy were considered. The changes of average energy gap of the chemical bond Mo-O and the environmental factor (h_e) surrounding Mo⁶⁺ ions in the crystals were discussed quantitatively. Calculated results from two different methods analysis specifications showed that the origin of CT blue-shifts mainly come from the vacancies of O6 sites within the crystals.