TY - JOUR
T1 - Higherature Annealing of CdZnTe Detectors
AU - Suh, J.
AU - Hwang, S.
AU - Yu, H.
AU - Yoon, Y.
AU - Bolotnikov, Aleksey E.
AU - James, Ralph B.
AU - Hong, J.
AU - Kim, Kihyun
N1 - Funding Information:
Manuscript received August 25, 2017; revised November 2, 2017; accepted November 4, 2017. Date of publication November 10, 2017; date of current version December 14, 2017. This work was supported in part by the National Research Foundation of Korea through the Ministry of Science, ICT, and Future Planning, South Korea, under Grant NRF-2015M2B2A9032788. J. Suh and J. Hong are with the Department of Applied Physics, Korea University, Sejong 30019, South Korea. S. Hwang and H. Yu are with the Department of Bio-convergence, Korea University, Seoul 02841, South Korea. Y. Yoon is with the Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan. A. E. Bolotnikov is with the Brookhaven National Laboratory, Upton, NY 11971 USA. R. B. James is with the Sivannah River National Laboratory, Aiken, SC 29808 USA. K. Kim is with the Department of Radiology, School of Health and Environmental Science, Korea University, Seoul 02841, South Korea (e-mail: khkim1@korea.ac.kr). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TNS.2017.2771378
Publisher Copyright:
© 1963-2012 IEEE.
PY - 2017/12
Y1 - 2017/12
N2 - The electrical properties of CdZnTe(CZT) above the melting point of tellurium (Te) inclusions were determined during in situ annealing. The thermal annealing cycles of the CZT detectors were 490 °C, 530 °C, and 570 °C continuously, which were higher than the melting points of elemental Te and Te inclusions and lower than the sublimation temperature of CZT. Unexpectedly, the CZT detectors exhibited very low leakage current at room temperature after the thermal annealing cycles due to the formation of rectifying contacts. The activation energy of high-resistivity CZT was 0.81 eV indicating pinning of Fermi level nearly in the middle of bandgap. At room temperature, CZT detectors with rectifying contacts showed clearly the 59.5-keV gamma-ray peak of Am-241. Observed fluctuations of the leakage current at about 470 °C might have originated from a mixed conductivity of liquid and solid CZT due to the melting of Te inclusions.
AB - The electrical properties of CdZnTe(CZT) above the melting point of tellurium (Te) inclusions were determined during in situ annealing. The thermal annealing cycles of the CZT detectors were 490 °C, 530 °C, and 570 °C continuously, which were higher than the melting points of elemental Te and Te inclusions and lower than the sublimation temperature of CZT. Unexpectedly, the CZT detectors exhibited very low leakage current at room temperature after the thermal annealing cycles due to the formation of rectifying contacts. The activation energy of high-resistivity CZT was 0.81 eV indicating pinning of Fermi level nearly in the middle of bandgap. At room temperature, CZT detectors with rectifying contacts showed clearly the 59.5-keV gamma-ray peak of Am-241. Observed fluctuations of the leakage current at about 470 °C might have originated from a mixed conductivity of liquid and solid CZT due to the melting of Te inclusions.
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U2 - 10.1109/TNS.2017.2771378
DO - 10.1109/TNS.2017.2771378
M3 - Article
AN - SCOPUS:85034255503
SN - 0018-9499
VL - 64
SP - 2966
EP - 2969
JO - IEEE Transactions on Nuclear Science
JF - IEEE Transactions on Nuclear Science
IS - 12
M1 - 8103821
ER -