Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-28T01:20:53.809Z Has data issue: false hasContentIssue false
  • English
  • Français

Characterization of Extended Defects Observed in Cadmium Zinc Telluride (CZT) Crystal

Published online by Cambridge University Press:  28 May 2015

Samuel Uba ,
Stephen Babalola ,
Anwar Hossain  and
Ralph James
Samuel Uba
Affiliation:
Alabama A&M University, Normal, AL 35811, U.S.A
Stephen Babalola
Affiliation:
Alabama A&M University, Normal, AL 35811, U.S.A
Anwar Hossain
Affiliation:
Nonproliferation and national security, Brookhaven National Laboratory, Upton, NY 11973, U.S.A
Ralph James
Affiliation:
Nonproliferation and national security, Brookhaven National Laboratory, Upton, NY 11973, U.S.A
Get access

Abstract

Cadmium Zinc Telluride (CZT) semiconductor crystal properties have been studied extensively with a focus on correlations to their radiation detector performance. The need for defect-free CZT crystal is imperative for optimal detector performance. Extended defects like Tellurium (Te) inclusions, twins, sub-grain boundaries, and dislocations are common defects found in CZT crystals; they alter the electrical properties and, therefore, the crystal's response to high energy radiation. In this research we studied the extended defects in CZT crystals from two separate ingots grown using the low-pressure Bridgman technique. We fabricated several detectors cut from wafers of two separate ingots by dicing, lapping, polishing, etching and applying gold metal contacts on the main surfaces of the crystals. Using infrared (IR) transmission microscope we analyzed the defects observed in the CZT detectors, showing three dimensional scans and plot size distributions of Te inclusions, twins and sub-grain boundaries observed in particular regions of the CZT detectors. We characterized electrical properties of the detectors by measuring bulk resistivity and detector response to gamma radiation. We observed that CZT detectors with more extended defects showed poor opto-electrical properties compared to detectors with fewer defects.

Keywords

crystaldefectsgrain boundaries
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1792: Symposium CC/FF – Defects and Materials Issues in Semiconductors―Relationship to Optoelectronic Properties and Device Reliability , 2015 , mrss15-2134263
Copyright
Copyright © Materials Research Society 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Milbrath, B.D., Peurrung, A.J., Bliss, M., and Weber, W.J.: Radiation detector materials: An overview. J. Mater. Res., Vol. 23, No. 10, (Oct 2008).CrossRefGoogle Scholar
Teague, Lucile C., Duff, Martine C., Cadieux, James R., RajiSoundararajan, Charles R. ShickJr, Kelvin G. Lynn: Characterization of etch pit formation via the Everson-etching method on CdZnTe crystal surfaces from the bulk to the nanoscale. Nuclear Instruments and Methods in Physics Research A 652 (2011) 178–182.CrossRefGoogle Scholar
Hossain, A., Babalola, S., Bolotnikov, A. E., Camarda, G. S., Cui, Y., Yang, G., Guo, M., Kochanowska, D., Mycielski, A., Burge, A. and James, R. B.: Effect of chemical etching on the surface roughness of CdZnTe and CdMnTe gamma radiation detectors. BNL-81418-2008-CP.Google Scholar
Synchrotron White Beam X‐Ray Topography X19C. Brookhaven National Laboratory (BNL) Upton, NY 11973.Google Scholar
Black, David R., Long, Gabrielle G.: X-Ray Topography. Material Science and Technology Laboratory (April 2004), Nist special publication 960-10.CrossRefGoogle Scholar
Bolotnikov, A.E., Babalola, S., Camarda, G.S., Cui, Y., Egarievwe, S.U., Hossain, A., Yang, G., and James, R.B.: Material Properties Limiting the Performance of CZT Gamma-Ray Detectors.Google Scholar
Prokescha, Michael and Szeles, Csaba: Accurate measurement of electrical bulk resistivity and surface leakage of CdZnTe radiation detector crystals. Journal of Applied Physics 100, 014503 (2006).CrossRefGoogle Scholar
Uri Lachish: CdTe and CdZnTe Crystal growth and fabrication of gamma radiation detectors guma science, P.O. Box 2104, Rehovot 76120, Israel .Google Scholar