TY - JOUR
T1 - Impurity-induced deep centers in Tl6SI4
AU - Shi, Hongliang
AU - Lin, Wenwen
AU - Kanatzidis, Mercouri G.
AU - Szeles, Csaba
AU - Du, Mao Hua
N1 - Funding Information:
This work was supported by the Department of Homeland Security, Domestic Nuclear Detection Office (Grant No. HSHQDC-14-R-B0009). H. Shi was supported in part by the National Natural Science Foundation of China (NSFC) under Grants No. 11604007. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
PY - 2017/4/14
Y1 - 2017/4/14
N2 - Tl6SI4 is a promising material for room-temperature semiconductor radiation detection applications. The history of the development of semiconductor radiation detection materials has demonstrated that impurities strongly affect the carrier transport and that material purification is a critically important step in improving the carrier transport and thereby the detector performance. Here, we report combined experimental and theoretical studies of impurities in Tl6SI4. Impurity concentrations in Tl6SI4 were analyzed by glow discharge mass spectrometry. Purification of the raw material by multi-pass vertical narrow zone refining was found to be effective in reducing the concentrations of most impurities. Density functional theory calculations were also performed to study the trapping levels introduced by the main impurities detected in experiments. We show that, among dozens of detected impurities, most are either electrically inactive or shallow. In the purified Tl6SI4 sample, only Bi has a significant concentration (0.2 ppm wt) and introduces deep electron trapping levels in the band gap. Improvement of the purification processes is expected to further reduce the impurity concentrations and their impact on carrier transport in Tl6SI4, leading to improved detector performance.
AB - Tl6SI4 is a promising material for room-temperature semiconductor radiation detection applications. The history of the development of semiconductor radiation detection materials has demonstrated that impurities strongly affect the carrier transport and that material purification is a critically important step in improving the carrier transport and thereby the detector performance. Here, we report combined experimental and theoretical studies of impurities in Tl6SI4. Impurity concentrations in Tl6SI4 were analyzed by glow discharge mass spectrometry. Purification of the raw material by multi-pass vertical narrow zone refining was found to be effective in reducing the concentrations of most impurities. Density functional theory calculations were also performed to study the trapping levels introduced by the main impurities detected in experiments. We show that, among dozens of detected impurities, most are either electrically inactive or shallow. In the purified Tl6SI4 sample, only Bi has a significant concentration (0.2 ppm wt) and introduces deep electron trapping levels in the band gap. Improvement of the purification processes is expected to further reduce the impurity concentrations and their impact on carrier transport in Tl6SI4, leading to improved detector performance.
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U2 - 10.1063/1.4980174
DO - 10.1063/1.4980174
M3 - Article
AN - SCOPUS:85017567696
VL - 121
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 14
M1 - 145102
ER -