期刊
PHYSICAL REVIEW APPLIED
卷 2, 期 4, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevApplied.2.044009
关键词
-
资金
- Siemens Medical Solutions Molecular Imaging
- National Nature Science Foundation of China [51202276]
- Shanghai Institute of Ceramics Innovation Program [Y39ZC2130G]
- State Key Laboratory of Crystal Material [KF1305]
- National Nuclear Security Administration, DNN R&D, through Lawrence Berkeley National Laboratory [DE-AC02-05CH1123]
- U.S. Department of Homeland Security, DNDO [NSF ECCS-1348361]
- Div Of Electrical, Commun & Cyber Sys
- Directorate For Engineering [1348361] Funding Source: National Science Foundation
To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12:Ce (GGAG:Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+ codoping content and the Ce4+ fraction is seen. The energy-level diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d(1) state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据