Purification and Improved Nuclear Radiation Detection of Tl6SI4 Semiconductor

Wenwen Lin, Zhifu Liu, Constantinos C. Stoumpos, Sanjib Das, Yihui He, Ido Hadar, John A. Peters, Kyle M. McCall, Yadong Xu, Duck Young Chung, Bruce W. Wessels, Mercouri G. Kanatzidis*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


The wide-band-gap semiconductor Tl6SI4 (2.14 eV) has high photon stopping power and is a promising material for detecting X-rays. In order to improve its photoresponse to low-flux γ-rays, material purification prior to crystal growth is crucial. In this contribution, we report effective purification protocols, impurity analysis, followed by synthesis and crystal growth, charge transport, and detector performance of large-sized Tl6SI4 crystals. Purification methods of evaporation and zone refining were developed, and their high effectiveness was confirmed by impurity analysis via glow discharge mass spectrometry. Centimeter-sized single crystals were grown using the Bridgman method. The improved properties after material purification were confirmed by photoluminescence measurements. The energy of the valence band maximum of a Tl6SI4, measured with photoemission spectroscopy in air (PESA), is ∼5.34 ± 0.05 eV. Detector devices fabricated from the single crystal exhibit a high resistivity of 5 × 1012 ω·cm. The detector shows promising photoresponse under 22.4 keV Ag Kα X-rays and 122 keV γ-rays from 57Co. Spectroscopic energy resolution was achieved for 5.5 MeV α-particles from a 241Am radiation source with a full width at half-maximum of 27% at an electric field intensity of 2500 V·cm-1. On the basis of its spectral response to 57Co γ-rays, the electron mobility-lifetime product μeτe was estimated as 1.4 × 10-5 cm2·V-1.

Original languageAmerican English
Pages (from-to)4738-4744
Number of pages7
JournalCrystal Growth and Design
Issue number8
StatePublished - 7 Aug 2019
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2019 American Chemical Society.


Dive into the research topics of 'Purification and Improved Nuclear Radiation Detection of Tl6SI4 Semiconductor'. Together they form a unique fingerprint.

Cite this