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Title: The investigation of custom grown vertical zone melt semi-insulating bulk gallium arsenide as a radiation spectrometer

Abstract

Vertical zone melt (VZM) bulk GaAs boules have been zone refined (ZR) and zone leveled (ZL) to reduce EL2 deep donor levels and impurity concentrations with the intent of improving properties for gamma ray detectors. Zr and Zl GaAs boules had background impurity levels and deep donor EL2 concentrations near or below detectable limits. The crystal mosaic of the material at locations near the seed end was slightly superior to commercial liquid encapsulated Czochralski (LEC) material, and nearly equivalent to commercial vertical gradient freeze (VGF) material. The crystal mosaic in ZL material degraded towards the tail end. The homogeneity of the electrical properties for the ZL and ZR VZM material was inferior compared to commercially available bulk GaAs material. Post growth annealing may help to homogenize some electrical properties of the material. The charge collection efficiency of the ZR GaAs detectors was only 30% maximum, and only 25% maximum for the ZL GaAs detectors. Resulting gamma ray spectra was poor from detectors fabricated with the ZL or ZR VZM material. Detectors fabricated from material that was both ZR and ZL did not demonstrate gamma ray resolution, and operated mainly as counters. The poor spectroscopic performance is presently attributed to themore » inhomogeneity of the electrical properties of the ZR and ZL GaAs materials. Comparisons are made with detectors fabricated from VGF SI bulk GaAs.« less

Authors:
;  [1];  [2]
  1. Sandia National Labs., Livermore, CA (United States)
  2. Sandia National Labs., Albuquerque, NM (United States); and others
Publication Date:
OSTI Identifier:
277692
Report Number(s):
CONF-951073-
Journal ID: IETNAE; ISSN 0018-9499; TRN: 96:018130
Resource Type:
Journal Article
Journal Name:
IEEE Transactions on Nuclear Science
Additional Journal Information:
Journal Volume: 43; Journal Issue: 3Pt2; Conference: IEEE nuclear science symposium and medical imaging conference, San Francisco, CA (United States), 21-28 Oct 1995; Other Information: PBD: Jun 1996
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; 36 MATERIALS SCIENCE; GAMMA SPECTROMETERS; MATERIALS; PERFORMANCE; GALLIUM ARSENIDES; ZONE REFINING; ZONE MELTING; ELECTRICAL PROPERTIES; GAMMA DETECTION; BULK SEMICONDUCTOR DETECTORS; COMPARATIVE EVALUATIONS

Citation Formats

McGregor, D S, Antolak, A J, and Chui, H C. The investigation of custom grown vertical zone melt semi-insulating bulk gallium arsenide as a radiation spectrometer. United States: N. p., 1996. Web. doi:10.1109/23.507073.
McGregor, D S, Antolak, A J, & Chui, H C. The investigation of custom grown vertical zone melt semi-insulating bulk gallium arsenide as a radiation spectrometer. United States. https://doi.org/10.1109/23.507073
McGregor, D S, Antolak, A J, and Chui, H C. Sat . "The investigation of custom grown vertical zone melt semi-insulating bulk gallium arsenide as a radiation spectrometer". United States. https://doi.org/10.1109/23.507073.
@article{osti_277692,
title = {The investigation of custom grown vertical zone melt semi-insulating bulk gallium arsenide as a radiation spectrometer},
author = {McGregor, D S and Antolak, A J and Chui, H C},
abstractNote = {Vertical zone melt (VZM) bulk GaAs boules have been zone refined (ZR) and zone leveled (ZL) to reduce EL2 deep donor levels and impurity concentrations with the intent of improving properties for gamma ray detectors. Zr and Zl GaAs boules had background impurity levels and deep donor EL2 concentrations near or below detectable limits. The crystal mosaic of the material at locations near the seed end was slightly superior to commercial liquid encapsulated Czochralski (LEC) material, and nearly equivalent to commercial vertical gradient freeze (VGF) material. The crystal mosaic in ZL material degraded towards the tail end. The homogeneity of the electrical properties for the ZL and ZR VZM material was inferior compared to commercially available bulk GaAs material. Post growth annealing may help to homogenize some electrical properties of the material. The charge collection efficiency of the ZR GaAs detectors was only 30% maximum, and only 25% maximum for the ZL GaAs detectors. Resulting gamma ray spectra was poor from detectors fabricated with the ZL or ZR VZM material. Detectors fabricated from material that was both ZR and ZL did not demonstrate gamma ray resolution, and operated mainly as counters. The poor spectroscopic performance is presently attributed to the inhomogeneity of the electrical properties of the ZR and ZL GaAs materials. Comparisons are made with detectors fabricated from VGF SI bulk GaAs.},
doi = {10.1109/23.507073},
url = {https://www.osti.gov/biblio/277692}, journal = {IEEE Transactions on Nuclear Science},
number = 3Pt2,
volume = 43,
place = {United States},
year = {1996},
month = {6}
}