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Title: An Effective Purification Process for the Nuclear Radiation Detector Tl 6 SeI 4

Abstract

The semiconductor Tl6SeI4 was previously identified as a promising semiconductor for room temperature nuclear radiation detection. As the detection performance and carrier transport strongly depend on the concentration of impurity energy levels acting as scattering centers and carrier trapping, material purification is a crucial prerequisite step to obtain spectroscopic-grade detector performance. In this contribution, we present a highly efficient purification method using a bent ampule for evaporating Se, Tl2Se, and TlI precursors for Tl6Se4. On the basis of impurity analysis performed by glow discharge mass spectroscopy, the main impurities in Tl2Se were identified to be Pb, Bi, and Al, while in TlI the main impurities are Al and Sn. The bent-ampule method successfully reduces or removes the Cl, Pb, and Te impurities from the Se precursor, the Pb, Bi, and Al impurities from the Tl2Se precursor, and removes Sn from TU. Informed by the analysis results, density functional theory calculations were performed to study the identified impurities and related defects. The calculation results show that Bi and Al act as deep defect levels, which can be detrimental to the detector performance of Tl6SeI4. If the growth condition of Tl6SeI4 is Tl-rich/Se-poor, impurity of Si can introduce deep donors. However, itmore » becomes electrically benign if growth conditions are Tl-poor/Se-rich, while Sn and Pb impurities are shallow donors. Centimeter-size Tl6SeI4 crystals were grown by the two-zone vertical Bridgman method using the purified precursors. The detector made of Tl6SeI4 crystal maintains the high resistivity on the order of 10(11) Omega.cm after purification, ideal for suppressing leakage current. The detector exhibits both full-energy and Tl escape photopeaks upon 122 keV gamma-ray from Co-57 radiation source. The electron mobility-lifetime product mu(e)tau(e) for TI6SeI4 detector is 8.1 X 10(-5) cm(2).V-1. On the basis of the carrier rise time measured from output pulses induced by 5.5 MeV alpha-particles from Am-241, the electron and hole mobilities were estimated to be 112 +/- 22 and 81 +/- 16 cm(2).V-1.s(-1), respectively, comparable to those of the leading detector materials HgI2 and TlBr. These results validate the potential of this compound for hard radiation detection, and the impurity analysis presented here allows future efforts to focus on reducing the concentration of the identified impurities.« less

Authors:
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  1. Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
US Department of Homeland Security (DHS)
OSTI Identifier:
1466339
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Crystal Growth and Design
Additional Journal Information:
Journal Volume: 18; Journal Issue: 6; Journal ID: ISSN 1528-7483
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English

Citation Formats

Lin, Wenwen, Kontsevoi, Oleg Y., Liu, Zhifu, Das, Sanjib, He, Yihui, Xu, Yadong, Stoumpos, Constantinos C., McCall, Kyle M., Rettie, Alexander J. E., Chung, Duck Young, Wessels, Bruce W., and Kanatzidis, Mercouri G. An Effective Purification Process for the Nuclear Radiation Detector Tl 6 SeI 4. United States: N. p., 2018. Web. doi:10.1021/acs.cgd.8b00242.
Lin, Wenwen, Kontsevoi, Oleg Y., Liu, Zhifu, Das, Sanjib, He, Yihui, Xu, Yadong, Stoumpos, Constantinos C., McCall, Kyle M., Rettie, Alexander J. E., Chung, Duck Young, Wessels, Bruce W., & Kanatzidis, Mercouri G. An Effective Purification Process for the Nuclear Radiation Detector Tl 6 SeI 4. United States. doi:10.1021/acs.cgd.8b00242.
Lin, Wenwen, Kontsevoi, Oleg Y., Liu, Zhifu, Das, Sanjib, He, Yihui, Xu, Yadong, Stoumpos, Constantinos C., McCall, Kyle M., Rettie, Alexander J. E., Chung, Duck Young, Wessels, Bruce W., and Kanatzidis, Mercouri G. Wed . "An Effective Purification Process for the Nuclear Radiation Detector Tl 6 SeI 4". United States. doi:10.1021/acs.cgd.8b00242.
@article{osti_1466339,
title = {An Effective Purification Process for the Nuclear Radiation Detector Tl 6 SeI 4},
author = {Lin, Wenwen and Kontsevoi, Oleg Y. and Liu, Zhifu and Das, Sanjib and He, Yihui and Xu, Yadong and Stoumpos, Constantinos C. and McCall, Kyle M. and Rettie, Alexander J. E. and Chung, Duck Young and Wessels, Bruce W. and Kanatzidis, Mercouri G.},
abstractNote = {The semiconductor Tl6SeI4 was previously identified as a promising semiconductor for room temperature nuclear radiation detection. As the detection performance and carrier transport strongly depend on the concentration of impurity energy levels acting as scattering centers and carrier trapping, material purification is a crucial prerequisite step to obtain spectroscopic-grade detector performance. In this contribution, we present a highly efficient purification method using a bent ampule for evaporating Se, Tl2Se, and TlI precursors for Tl6Se4. On the basis of impurity analysis performed by glow discharge mass spectroscopy, the main impurities in Tl2Se were identified to be Pb, Bi, and Al, while in TlI the main impurities are Al and Sn. The bent-ampule method successfully reduces or removes the Cl, Pb, and Te impurities from the Se precursor, the Pb, Bi, and Al impurities from the Tl2Se precursor, and removes Sn from TU. Informed by the analysis results, density functional theory calculations were performed to study the identified impurities and related defects. The calculation results show that Bi and Al act as deep defect levels, which can be detrimental to the detector performance of Tl6SeI4. If the growth condition of Tl6SeI4 is Tl-rich/Se-poor, impurity of Si can introduce deep donors. However, it becomes electrically benign if growth conditions are Tl-poor/Se-rich, while Sn and Pb impurities are shallow donors. Centimeter-size Tl6SeI4 crystals were grown by the two-zone vertical Bridgman method using the purified precursors. The detector made of Tl6SeI4 crystal maintains the high resistivity on the order of 10(11) Omega.cm after purification, ideal for suppressing leakage current. The detector exhibits both full-energy and Tl escape photopeaks upon 122 keV gamma-ray from Co-57 radiation source. The electron mobility-lifetime product mu(e)tau(e) for TI6SeI4 detector is 8.1 X 10(-5) cm(2).V-1. On the basis of the carrier rise time measured from output pulses induced by 5.5 MeV alpha-particles from Am-241, the electron and hole mobilities were estimated to be 112 +/- 22 and 81 +/- 16 cm(2).V-1.s(-1), respectively, comparable to those of the leading detector materials HgI2 and TlBr. These results validate the potential of this compound for hard radiation detection, and the impurity analysis presented here allows future efforts to focus on reducing the concentration of the identified impurities.},
doi = {10.1021/acs.cgd.8b00242},
journal = {Crystal Growth and Design},
issn = {1528-7483},
number = 6,
volume = 18,
place = {United States},
year = {2018},
month = {4}
}