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

Title: Assessment of a new ZnO:Al contact to CdZnTe for X- and gamma-ray detector applications

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1];  [1];  [2];  [2];  [1]
  1. Brookhaven National Laboratory, Upton, New York 11973, USA
  2. Department of Engineering, Norfolk State University, Norfolk, Virginia 23504, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1394007
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
AIP Advances
Additional Journal Information:
Journal Volume: 7; Journal Issue: 9; Related Information: CHORUS Timestamp: 2018-02-14 21:00:02; Journal ID: ISSN 2158-3226
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Roy, U. N., Camarda, G. S., Cui, Y., Gul, R., Hossain, A., Yang, G., Mundle, R. M., Pradhan, A. K., and James, R. B.. Assessment of a new ZnO:Al contact to CdZnTe for X- and gamma-ray detector applications. United States: N. p., 2017. Web. doi:10.1063/1.5001701.
Roy, U. N., Camarda, G. S., Cui, Y., Gul, R., Hossain, A., Yang, G., Mundle, R. M., Pradhan, A. K., & James, R. B.. Assessment of a new ZnO:Al contact to CdZnTe for X- and gamma-ray detector applications. United States. doi:10.1063/1.5001701.
Roy, U. N., Camarda, G. S., Cui, Y., Gul, R., Hossain, A., Yang, G., Mundle, R. M., Pradhan, A. K., and James, R. B.. Fri . "Assessment of a new ZnO:Al contact to CdZnTe for X- and gamma-ray detector applications". United States. doi:10.1063/1.5001701.
@article{osti_1394007,
title = {Assessment of a new ZnO:Al contact to CdZnTe for X- and gamma-ray detector applications},
author = {Roy, U. N. and Camarda, G. S. and Cui, Y. and Gul, R. and Hossain, A. and Yang, G. and Mundle, R. M. and Pradhan, A. K. and James, R. B.},
abstractNote = {},
doi = {10.1063/1.5001701},
journal = {AIP Advances},
number = 9,
volume = 7,
place = {United States},
year = {Fri Sep 01 00:00:00 EDT 2017},
month = {Fri Sep 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.5001701

Save / Share:
  • The poor adhesion of common metals to CdZnTe (CZT)/CdTe surfaces has been a long-standing challenge for radiation detector applications. In this present work, we explored the use of an alternative electrode, viz., Al-doped ZnO (AZO) as a replacement to common metallic contacts. ZnO offers several advantages over the latter, such as having a higher hardness, a close match of the coefficients of thermal expansion for CZT and ZnO, and better adhesion to the surface of CZT due to the contact layer being an oxide. The AZO/CZT contact was investigated via high spatial-resolution X-ray response mapping for a planar detector atmore » the micron level. The durability of the device was investigated by acquiring I–V measurements over an 18-month period, and good long-term stability was observed. We have demonstrated that the AZO/CZT/AZO virtual-Frisch-grid device performs fairly well, with comparable or better characteristics than that for the same detector fabricated with gold contacts.« less
  • Cited by 1
  • Corrosion under insulation (CUI) on the external wall of steel pipes is a common problem in many types of industrial plants. This is mainly due to the presence of moisture or water in the insulation materials. This type of corrosion can cause failures in areas that are not normally of a primary concern to an inspection program. The failures are often the result of localised corrosion and not general wasting over a large area. These failures can tee catastrophic in nature or at least have an adverse economic effect in terms of downtime and repairs. There are a number ofmore » techniques used today for CUI investigations. The main ones are profile radiography, pulse eddy current, ultrasonic spot readings and insulation removal. A new system now available is portable Pipe-CUI-Profiler. The nucleonic system is based on dual-beam gamma-ray absorption technique using Cadmium Zinc Telluride (CdZnTe) semiconductor detectors. The Pipe-CUI-Profiler is designed to inspect pipes of internal diameter 50, 65, 80, 90, 100, 125 and 150 mm. Pipeline of these sizes with aluminium or thin steel sheathing, containing fibreglass or calcium silicate insulation to thickness of 25, 40 and 50 mm can be inspected. The system has proven to be a safe, fast and effective method of inspecting pipe in industrial plant operations. This paper describes the application of gamma-ray techniques and CdZnTe semiconductor detectors in the development of Pipe-CUI-Profiler for non-destructive imaging of corrosion under insulation of steel pipes. Some results of actual pipe testing in large-scale industrial plant will be presented.« less
  • A CdZnTe detector grown by the high pressure Bridgman (HPB) growth technique was tested using high energy x-rays (30{approx}100 keV), and the performance was compared with a commercially available Nal scintillating detector of 5 cm thickness. The charge collection efficiency of a CdZnTe detector is as high as 90% at relatively low electric field, 600 V/cm. At high x-ray photon energies, the detection efficiency is reduced due to the thickness of the CdZnTe. A 32 channel linear array was fabricated on 1.2{approx}1.7 mm thick CdZnTe, of which the detector area was 175 x 800 {micro}m{sup 2} and the pitch sizemore » 250 {micro}m. The measured dark current for the 16 element detector was as low as 0.1 pA at 800 V/cm with an excellent uniformity. Energy spectra were measured using a Co{sup 57} radiation source. A small pixel effect and charge sharing were observed. The energy resolution was improved and compared with the large area detector. The array detector gave an average 5.8% full-width-half-maximum (FWHM) at 122 keV photopeak. The large area detector of the same material before fabrication exhibited a low energy tail at the photopeak, which limits the photopeak FWHM to 8%.« less
  • We present the results of an experimental study of a special type of CdZnTe detector of hard x and {gamma} rays--A-drift detector. The device consists of a double ring electrode structure surrounding a central point anode with a guard plane surrounding the outer anode ring. The detector can be operated in two distinctively different modes of charge collection--pseudohemispherical and pseudodrift. We study the detector response profiles obtained by scanning the focused x-ray beam over the whole detector area, specifically the variations in count rate, peak position, and energy resolution for x rays from 10 to 100 keV. In addition, atmore » 662 keV the energy resolution was shown to be 4.8 keV, more than a factor of 2 better than for CdZnTe coplanar grid detectors. To interpret the experimental data, we derive an analytical expression for the spatial distribution of the electric field inside the detector and neglecting carrier diffusion, and identify carrier collection patterns for both modes of operation within the drift model approximation. We show that this model provides a good understanding of measured profiles.« less