Judd-Ofelt Intensity Parameters and Spectral Properties of Gd2O3:Eu3+ Nanocrystals
详细信息 查看全文
- 作者：Chunxu Liu ; Junye Liu ; Kai Dou
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：October 19, 2006
- 年：2006
- 卷：110
- 期：41
- 页码：20277 - 20281
- 全文大小：139K
- 年卷期：v.110,no.41(October 19, 2006)
- ISSN：1520-5207
文摘
Three nonequivalent centers of Cs (A, B, and C) in monoclinic phase and C2 and S6 centers in cubic phasewere identified in the Gd2O3:Eu3+ nanocrystals with spectral techniques. Size dependence in the spectraindicated that the excitations from both host and charge-transfer band (CTB) for the 5D0 
7F2 transition ofEu3+ ions were nearly equal for a larger size of 135 nm of the cubic phase; however, with decreasing the sizeto or less than 23 nm, the excitations by the CTB dominated. The variation of excitation leading to thesymmetry and energy change in the C2 and S6 sites was also observed for larger particle sizes. The Judd-Ofelt intensity parameters 
( = 2, 4) for Gd2O3:Eu3+ nanoparticles were experimentally determined. Theparameters were found to significantly change with the sizes of Gd2O3:Eu3+ from nanoparticles to bulkmaterial. With decreasing the size from 135 to 15 nm, the quantum efficiencies for 5D0 reduced from 23.6%to 4.6% due to the increasing ratio of surface to volume.
7F2 transition ofEu3+ ions were nearly equal for a larger size of 135 nm of the cubic phase; however, with decreasing the sizeto or less than 23 nm, the excitations by the CTB dominated. The variation of excitation leading to thesymmetry and energy change in the C2 and S6 sites was also observed for larger particle sizes. The Judd-Ofelt intensity parameters ( = 2, 4) for Gd2O3:Eu3+ nanoparticles were experimentally determined. Theparameters were found to significantly change with the sizes of Gd2O3:Eu3+ from nanoparticles to bulkmaterial. With decreasing the size from 135 to 15 nm, the quantum efficiencies for 5D0 reduced from 23.6%to 4.6% due to the increasing ratio of surface to volume.