摘要
The electronic and defect energy level structure of polyerystalline Sr2MgSi2OT：Eu^2＋,R^3＋ persistent luminescence materials were studied with thermoluminescence and different synchrotron radiation spectroscopies （UV-VUV emission and excitation, X-ray absorption near-edge spectroscopy （XANES） and extended X-ray absorption f＇me structure （EXAFS））. Special attention was paid on the effect of the R3＋ co-dopants on the persistent luminescence properties of the materials. Theoretical calculations using the density functional theory （DFT） were carried out simultaneously with the experimental work. The experimental band gap energy （Eg） value of ca. 7.1 eV agreed very well with the DFT value of 6.7 eV. The variation of the Eg value was attempted to relate with the trap structure as well as with the different properties of the R3＋ co-dopants. The trap level energy distribution depended strongly on the R3＋ co-dopant except for the shallowest trap energy above the room temperature remaining practically the same, however. The different processes in the mechanism of persistent luminescence from Sr2MgSi2OT：Eu^2＋,R^3＋ were assembled and their contributions discussed.
The electronic and defect energy level structure of polyerystalline Sr2MgSi2OT：Eu^2＋,R^3＋ persistent luminescence materials were studied with thermoluminescence and different synchrotron radiation spectroscopies （UV-VUV emission and excitation, X-ray absorption near-edge spectroscopy （XANES） and extended X-ray absorption f＇me structure （EXAFS））. Special attention was paid on the effect of the R3＋ co-dopants on the persistent luminescence properties of the materials. Theoretical calculations using the density functional theory （DFT） were carried out simultaneously with the experimental work. The experimental band gap energy （Eg） value of ca. 7.1 eV agreed very well with the DFT value of 6.7 eV. The variation of the Eg value was attempted to relate with the trap structure as well as with the different properties of the R3＋ co-dopants. The trap level energy distribution depended strongly on the R3＋ co-dopant except for the shallowest trap energy above the room temperature remaining practically the same, however. The different processes in the mechanism of persistent luminescence from Sr2MgSi2OT：Eu^2＋,R^3＋ were assembled and their contributions discussed.
基金
Project supported by the Turku University Foundation, Jenny and Antti Wihuri Foundation (Finland) and the Academy of Finland (117057/2006)
supported by the European Community-Research Infrastructure Action under the FP6 Structuring the European Re-search Area Programme, RII3-CT-2004-506008 (IA-SFS)
supported by the Integrated Infrastructure Initiative "Integrating Activity on Synchrotron and Free Electron Laser Science"
supported by Research Mobility Agreements (112816/2006/JH and 116142/2006/JH, 123976/2007/TL) between the Academy of Finland and the Academy of Sciences of the Czech Republic
