Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Passivation effect on large volume CdZnTe crystals

  • B. Park (Dept. of Health and Safety Convergence Science, Korea University) ;
  • Y. Kim (Interdisciplinary Program in Precision Public Health, Korea University) ;
  • J. Seo (Dept. of Health and Safety Convergence Science, Korea University) ;
  • J. Byun (Dept. of Health and Safety Convergence Science, Korea University) ;
  • K. Kim (School of Health and Environmental Science, Korea University)
  • Received : 2022.04.19
  • Accepted : 2022.06.07
  • Published : 2022.12.25
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Abstract

Several cadmium zinc telluride (CZT) crystals were fabricated into radiation detectors using methods that included slicing, dicing, lapping, polishing, and chemical etching. A wet passivation with sodium hypochlorite (NaOCl) was then carried out on the Br-etched detectors. The Te-rich layer on the CZT surface was successfully compensated to the Te oxide layer, which was analyzed with X-ray photoelectron spectroscopy data of both a Br-etched crystal and a passivated CZT crystals. We confirmed that passivation with NaOCl improved the transport property by analyzing the mobility-lifetime product and surface recombination velocity. The electrical and spectroscopic properties of large volume detectors were compared before and after passivation, and then the detectors were observed for a month. Both bar and quasi-hemispherical detectors show an enhancement in performance after passivation. Thus, we could identify the effect of NaOCl passivation on large volume CZT detectors.

Keywords

Acknowledgement

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1A2C1012161), by Ministry of Environment as "the Graduate school of Particulate matter specialization" and by Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government (MOTIE) (20214000000070, Promoting of expert for energy industry advancement in the field of radiation technology).

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