Abstract
Cu2I2Se6 is a new wide-bandgap semiconductor with high stability and great potential toward hard radiation and photon detection. Cu2I2Se6 crystallizes in the rhombohedral R3?m space group with a density of d = 5.287 g·cm-3 and a wide bandgap Eg of 1.95 eV. First-principles electronic band structure calculations at the density functional theory level indicate an indirect bandgap and a low electron effective mass me∗ of 0.32. The congruently melting compound was grown in centimeter-size Cu2I2Se6 single crystals using a vertical Bridgman method. A high electric resistivity of ?1012 ?·cm is readily achieved, and detectors made of Cu2I2Se6 single crystals demonstrate high photosensitivity to Ag Kα X-rays (22.4 keV) and show spectroscopic performance with energy resolutions under 241Am α-particles (5.5 MeV) radiation. The electron mobility is measured by a time-of-flight technique to be ?46 cm2·V-1·s-1. This value is comparable to that of one of the leading ?-ray detector materials, TlBr, and is a factor of 30 higher than mobility values obtained for amorphous Se for X-ray detection.
Original language | English (US) |
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Pages (from-to) | 1894-1899 |
Number of pages | 6 |
Journal | Journal of the American Chemical Society |
Volume | 140 |
Issue number | 5 |
DOIs | |
State | Published - Feb 7 2018 |
Funding
This work is supported by DHS-ARI grant 2014-DN-077-ARI086-01. This work made use of the EPIC facility of the NUANCE Center and IMSERC at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205). Computing resources were provided by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
ASJC Scopus subject areas
- General Chemistry
- Biochemistry
- Catalysis
- Colloid and Surface Chemistry