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Title: Characterization of Low-Defect Cd0.9Zn0.1Te and CdTe Crystals for High-Performance Frisch Collar Detectors

Abstract

Low dislocation density, high-purity, and low inclusion concentration Cd{sub 0.9}Zn{sub 0.1}Te (CZT) and CdTe crystals were grown by a vertical Bridgman technique using in-house zone refined precursors. The grown crystals were sequentially processed using optimized chemo-mechanical processes to fabricate planar and Frisch collar detectors. Infrared transmission and scanning electron microscopy studies have shown that EIC grown CZT and CdTe crystals have significantly lower Te inclusions and defect densities than commercially available spectrometer grade crystals. The charge transport properties (electron and hole mobility-lifetime products, mutau{sub e} & mutau{sub h}) of various detectors have been evaluated by Hecht analysis. The detectors have been tested for spectral response using 59.5 and 662 keV gamma-ray sources. The CZT detectors with planar electrodes showed 2.6% FWHM at 662 keV. By adding a Frisch collar, the detectors' spectra improved significantly. The Frisch collar detectors proved to be very promising for assembling large-area arrays with excellent energy resolution at relatively low manufacturing cost.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930058
Report Number(s):
BNL-80685-2008-JA
Journal ID: ISSN 0018-9499; IETNAE; TRN: US0806688
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Nuclear Science; Journal Volume: 54
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CDTE SEMICONDUCTOR DETECTORS; ZINC TELLURIDES; CADMIUM TELLURIDES; DISLOCATIONS; BRIDGMAN METHOD; CHARGE TRANSPORT; ENERGY RESOLUTION; SPECTRAL RESPONSE; national synchrotron light source

Citation Formats

Mandal,K., Kang, S., Choi, M., Kargar, A., Harrison, M., McGregor, D., Bolotnikov, A., Carini, G., Camarda, G., and James, R. Characterization of Low-Defect Cd0.9Zn0.1Te and CdTe Crystals for High-Performance Frisch Collar Detectors. United States: N. p., 2007. Web. doi:10.1109/TNS.2007.902371.
Mandal,K., Kang, S., Choi, M., Kargar, A., Harrison, M., McGregor, D., Bolotnikov, A., Carini, G., Camarda, G., & James, R. Characterization of Low-Defect Cd0.9Zn0.1Te and CdTe Crystals for High-Performance Frisch Collar Detectors. United States. doi:10.1109/TNS.2007.902371.
Mandal,K., Kang, S., Choi, M., Kargar, A., Harrison, M., McGregor, D., Bolotnikov, A., Carini, G., Camarda, G., and James, R. Mon . "Characterization of Low-Defect Cd0.9Zn0.1Te and CdTe Crystals for High-Performance Frisch Collar Detectors". United States. doi:10.1109/TNS.2007.902371.
@article{osti_930058,
title = {Characterization of Low-Defect Cd0.9Zn0.1Te and CdTe Crystals for High-Performance Frisch Collar Detectors},
author = {Mandal,K. and Kang, S. and Choi, M. and Kargar, A. and Harrison, M. and McGregor, D. and Bolotnikov, A. and Carini, G. and Camarda, G. and James, R.},
abstractNote = {Low dislocation density, high-purity, and low inclusion concentration Cd{sub 0.9}Zn{sub 0.1}Te (CZT) and CdTe crystals were grown by a vertical Bridgman technique using in-house zone refined precursors. The grown crystals were sequentially processed using optimized chemo-mechanical processes to fabricate planar and Frisch collar detectors. Infrared transmission and scanning electron microscopy studies have shown that EIC grown CZT and CdTe crystals have significantly lower Te inclusions and defect densities than commercially available spectrometer grade crystals. The charge transport properties (electron and hole mobility-lifetime products, mutau{sub e} & mutau{sub h}) of various detectors have been evaluated by Hecht analysis. The detectors have been tested for spectral response using 59.5 and 662 keV gamma-ray sources. The CZT detectors with planar electrodes showed 2.6% FWHM at 662 keV. By adding a Frisch collar, the detectors' spectra improved significantly. The Frisch collar detectors proved to be very promising for assembling large-area arrays with excellent energy resolution at relatively low manufacturing cost.},
doi = {10.1109/TNS.2007.902371},
journal = {IEEE Transactions on Nuclear Science},
number = ,
volume = 54,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Spectrometer-grade CdTe single crystals with resistivities higher than 10{sup 9} {Omega} cm have been grown by the modified Bridgman method using zone-refined precursor materials (Cd and Te) under a Cd overpressure. The grown CdTe crystals had good charge-transport properties ({mu}{tau}{sub e} = 2 x 10{sup -3} cm{sup 2} V{sup -1}, {mu}{tau}{sub h} = 8 x 10{sup -5} cm{sup 2} V{sup -1}) and significantly reduced Te precipitates compared with crystals grown without Cd overpressure. The crystal growth conditions for the Bridgman system were optimized by computer modeling and simulation, using modified MASTRAPP program, and applied to crystal diameters of 14 mmmore » (0.55'), 38 mm (1.5'), and 76 mm (3'). Details of the CdTe crystal growth operation, structural, electrical, and optical characterization measurements, detector fabrication, and testing using {sup 241}Am (60 keV) and {sup 137}Cs (662 keV) sources are presented.« less
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