skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: High-resolution p-i-n CdTe and CdZnTe x-ray detectors with cooling and rise-time discrimination

Abstract

The leakage current of CdTe detectors can be significantly reduced by processing detector crystals with p-i-n structures. Leakage currents of the order of several nA/mm{sup 2} are achieved at room temperature which compares well with the leakage current of commercially available CdZnTe detectors. The leakage current can be reduced further by cooling the detector to about {minus}30 C, where values of about pA/mm{sup 2} are achieved. These low values enable the use of low-noise, pulsed-optical feedback preamplifiers and higher bias voltages. High bias voltage is necessary for efficient charge collection which reduces spectrum background and peak tailing. Applying rise time discrimination circuitry to the linear amplifier reduces the tailing effect even further, especially at higher radiation energies. The authors tested several 4 to 30-mm{sup 2}, 0.6 to 1-mm thick p-i-n structure CdTe detector crystals at {minus}20 to {minus}30 C with a low-noise pulsed-optical feedback preamplifier and rise-time discriminator, and at best obtained energy resolutions of 700 eV at the 59.5-keV line of {sup 241}Am, 1.2 keV at the 122-keV line of {sup 57}Co, and 2.5 keV at the 662-keV line of {sup 137}Cs. A similar p-i-n structure was processed on a 4-mm{sup 2} Cd{sub 0.9}Zn{sub 0.1}Te detector crystal in ordermore » to reduce its leakage current, and energy resolutions of 368 eV at the 5.9-keV line of {sup 55}Fe, 670 eV at the 59.5-keV line of {sup 241}Am, and 2.6 keV at the 662-keV line of {sup 137}Cs were obtained. However, the detector suffered from a charge collection problem yielding relatively high background under the peaks.« less

Authors:
;  [1];  [2]
  1. Metorex International Oy, Espoo (Finland)
  2. Baltic Scientific Instruments Ltd., Riga (Latvia)
Publication Date:
OSTI Identifier:
277703
Report Number(s):
CONF-951073-
Journal ID: IETNAE; ISSN 0018-9499; TRN: 96:018141
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; X-RAY DETECTION; CDTE SEMICONDUCTOR DETECTORS; TIMING CIRCUITS; LEAKAGE CURRENT; COOLING; SEMICONDUCTOR JUNCTIONS; AMBIENT TEMPERATURE; CADMIUM TELLURIDES; ZINC TELLURIDES; PULSE DISCRIMINATORS; PERFORMANCE; AMERICIUM 241; CESIUM 137; IRON 55

Citation Formats

Niemelae, A, Sipilae, H, and Ivanov, V I. High-resolution p-i-n CdTe and CdZnTe x-ray detectors with cooling and rise-time discrimination. United States: N. p., 1996. Web. doi:10.1109/23.507087.
Niemelae, A, Sipilae, H, & Ivanov, V I. High-resolution p-i-n CdTe and CdZnTe x-ray detectors with cooling and rise-time discrimination. United States. https://doi.org/10.1109/23.507087
Niemelae, A, Sipilae, H, and Ivanov, V I. Sat . "High-resolution p-i-n CdTe and CdZnTe x-ray detectors with cooling and rise-time discrimination". United States. https://doi.org/10.1109/23.507087.
@article{osti_277703,
title = {High-resolution p-i-n CdTe and CdZnTe x-ray detectors with cooling and rise-time discrimination},
author = {Niemelae, A and Sipilae, H and Ivanov, V I},
abstractNote = {The leakage current of CdTe detectors can be significantly reduced by processing detector crystals with p-i-n structures. Leakage currents of the order of several nA/mm{sup 2} are achieved at room temperature which compares well with the leakage current of commercially available CdZnTe detectors. The leakage current can be reduced further by cooling the detector to about {minus}30 C, where values of about pA/mm{sup 2} are achieved. These low values enable the use of low-noise, pulsed-optical feedback preamplifiers and higher bias voltages. High bias voltage is necessary for efficient charge collection which reduces spectrum background and peak tailing. Applying rise time discrimination circuitry to the linear amplifier reduces the tailing effect even further, especially at higher radiation energies. The authors tested several 4 to 30-mm{sup 2}, 0.6 to 1-mm thick p-i-n structure CdTe detector crystals at {minus}20 to {minus}30 C with a low-noise pulsed-optical feedback preamplifier and rise-time discriminator, and at best obtained energy resolutions of 700 eV at the 59.5-keV line of {sup 241}Am, 1.2 keV at the 122-keV line of {sup 57}Co, and 2.5 keV at the 662-keV line of {sup 137}Cs. A similar p-i-n structure was processed on a 4-mm{sup 2} Cd{sub 0.9}Zn{sub 0.1}Te detector crystal in order to reduce its leakage current, and energy resolutions of 368 eV at the 5.9-keV line of {sup 55}Fe, 670 eV at the 59.5-keV line of {sup 241}Am, and 2.6 keV at the 662-keV line of {sup 137}Cs were obtained. However, the detector suffered from a charge collection problem yielding relatively high background under the peaks.},
doi = {10.1109/23.507087},
url = {https://www.osti.gov/biblio/277703}, journal = {IEEE Transactions on Nuclear Science},
number = 3Pt2,
volume = 43,
place = {United States},
year = {1996},
month = {6}
}