title: Charge Transport and Observation of Persistent Photoconductivity in Tl6SeI4Single Crystals.
abstract: The chalcohalide compound Tl6SeI4is a promising wide-bandgap semiconductor for efficient hard radiation detection at room temperature due to its high density, average atomic number and mobility-lifetime product. However, the nature of its charge transport kinetics, especially the role of defects in recombination, has not been examined in detail. To determine the charge transport kinetics in Tl6SeI4single crystals, electrical conductivity and photoinduced current transient spectroscopy were measured over the temperature range 105-330 K. These measurements reveal the existence of multiple defect states with energy levels in the range 0.10-0.90 eV, within the bandgap of Tl6SeI4. Large persistent photoconductivity (PPC) is observed at low temperature that shows strong thermal quenching at 160 K. The quenching of PPC is described using a configuration coordinate model involving a deep level donor state, which is tentatively attributed to the presence of iodine vacancies or Si interstitial impurities.
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Sanjib
authors.identifier: http://orcid.org/0000-0002-5281-4458
authors.initials: S
authors.lastname: Das
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|Department of Chemistry and Physics, Chicago State University , Chicago, Illinois 60628, United States.
authors.forename: John A
authors.initials: JA
authors.lastname: Peters
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Svetlana S
authors.initials: SS
authors.lastname: Kostina
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Pice
authors.identifier: http://orcid.org/0000-0003-4401-5637
authors.initials: P
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Joon-Il
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.|Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Mercouri G
authors.identifier: http://orcid.org/0000-0003-2037-4168
authors.initials: MG
authors.lastname: Kanatzidis
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Bruce W
authors.identifier: http://orcid.org/0000-0002-8957-7097
authors.initials: BW
authors.lastname: Wessels