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Title: Scintillation properties and electronic structure of the intrinsic and extrinsic mixed elpasolites Cs 2 Na RBr 3I 3 ( R = La, Y)

Scintillators attract wide research interest for their distinct applications in radiation detection. Elpasolite halides are among the most promising scintillators due to their high structural symmetry and good scintillation performance. A better understanding of their underlying scintillation mechanism opens up possibilities in scintillator development. In this work, we employ a variety of experimental techniques to study the two mixed-anion elpasolites Cs 2Na RBr 3I 3 ( R = La, Y). The emission of intrinsic Cs 2Na RBr 3I 3 with a light yield ranging from 20 000 to 40 000 ph / MeV is dominant by self-trapped exciton emission. Partial substitution of R with Ce introduces a competing emission, the Ce 3+ 5d-to-4f radiative transition. Ab initio calculations are performed to investigate the electronic structures as well as the binding energies of polarons in Cs 2Na RBr 6. The calculated large self-trapped exciton binding energies are consistent with the observed high light yield due to self-trapped exciton (STE) emission. The unique electronic structure of halide elpasolites as calculated enhances the STE stability and the STE emission. The highly tunable scintillation properties of mixed-anion elpasolites underscore the role of their complex scintillation mechanism. Furthermore, our study provides guidance for the designmore » of elpasolite scintillators with exceptional energy resolution and light yield desirable for applications.« less
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [1] ;  [1] ;  [2]
  1. Univ. of Tennessee, Knoxville, TN (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Stanford Univ., Stanford, CA (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review Applied
Additional Journal Information:
Journal Volume: 5; Journal Issue: 2; Journal ID: ISSN 2331-7019
Publisher:
American Physical Society
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
OSTI Identifier:
1244201
Alternate Identifier(s):
OSTI ID: 1238410