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This content will become publicly available on April 16, 2019

Title: Stoichiometric Effects on the Photoelectric Properties of LiInSe 2 Crystals for Neutron Detection

6LiInSe 2 is a promising semiconductor candidate for thermal neutron detection due to its large capture cross-section. However, the charge collection efficiency is still insufficient for high resolution for the grown-in defects induced by the stoichiometric deviation. In this work, we report photoelectric properties of stoichiometric LiInSe 2 crystal boules up to 70 mm in length and 20 mm in diameter grown by the vertical Bridgman method. Inductively coupled plasma measurements demonstrate that the ratio of Li, In, and Se of the as-grown crystal is very close to 1:1:2, which is optimized by low temperature synthesis processing. The obtained single crystals display high bulk resistivity in the range of 10 11–10 12 Ω·cm and a direct band gap of 2.01–2.83 eV with a changeable color from red to yellow. The electronic structure of LiInSe 2 was studied using first-principles density functional theory calculations, which predicts that the antisite defects of In Li and Li In are the dominant factor for the different crystal colors observed. The stoichiometric LiInSe 2 crystal gives an improved energy resolution, for a semiconductor detector when illuminated with a 241Am@5.48 MeV α source, of 23.3%. In conclusion, the electron mobility-lifetime product (μτ) is ~2.5 × 10more » –5 cm 2 V –1.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1] ;  [2] ;  [2] ;  [2] ; ORCiD logo [2] ; ORCiD logo [3] ;  [2] ;  [4] ;  [2] ; ORCiD logo [5]
  1. Northwestern Polytechnical Univ., Xi'an (China); Northwestern Univ., Evanston, IL (United States)
  2. Northwestern Polytechnical Univ., Xi'an (China)
  3. Northwestern Univ., Evanston, IL (United States)
  4. Argonne National Lab. (ANL), Argonne, IL (United States)
  5. Northwestern Univ., Evanston, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Crystal Growth and Design
Additional Journal Information:
Journal Volume: 18; Journal Issue: 5; Journal ID: ISSN 1528-7483
Publisher:
American Chemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Natural Science Foundation of China (NNSFC); National Key Research and Development Program of China; Natural Science Basis Research Plan in Shaanxi Province of China; Argonne National Laboratory, Laboratory Directed Research and Development (LDRD); USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1437380