Investigation on the Luminescence Improvement of Nanosized La2O3/Eu3+ Phosphor under Charge-Transfer Excitation

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• 作者：Chunyu Shang ; Hongbo Jiang ; Xiaohong Shang ; Meicheng Li ; Liancheng Zhao
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：February 17, 2011
• 年：2011
• 卷：115
• 期：6
• 页码：2630-2635
• 全文大小：839K
• 年卷期：v.115,no.6(February 17, 2011)
• ISSN：1932-7455

文摘

When the size of La₂O₃/Eu³⁺ phosphor decreases to the nanoscale, the rigidity of the lattice environment is decreased, causing the enlargement of the charge-transfer state (CTS) coordinate offset for the optical centers in La₂O₃/Eu³⁺ nanophosphor. The enlargement of the CTS coordinate offset results in the decrease of the CTS feeding probability to the ⁵D states of Eu³⁺ ions in the optical centers. In addition, the energy transfer to the quenching centers in the surface leads to the decrease of the ⁵D emission efficiency of the excited Eu³⁺ ions. In view of these two quenching mechanisms of the optical centers, proper surface coating is adopted to improve the luminescence efficiency for La₂O₃/Eu³⁺ nanophosphor under CT excitation. The changes in the related parameters of La₂O₃/Eu³⁺ nanophosphor in the surface coating and the subsequent annealing process have been experimentally determined and objectively analyzed. By surface coating, the luminescence efficiency of La₂O₃/Eu³⁺ nanophosphor has been significantly improved.