5 years ago

Defect Antiperovskite Compounds Hg3Q2I2 (Q = S, Se, and Te) for Room-Temperature Hard Radiation Detection

Defect Antiperovskite Compounds Hg3Q2I2 (Q = S, Se, and Te) for Room-Temperature Hard Radiation Detection
Yihui He, Svetlana S. Kostina, Oleg Y. Kontsevoi, Giancarlo G. Trimarchi, Saiful M. Islam, Mercouri G. Kanatzidis, Sanjib Das, Constantinos C. Stoumpos, Wenwen Lin, Bruce W. Wessels, Joon-Il Kim, Zhifu Liu
The high Z chalcohalides Hg3Q2I2 (Q = S, Se, and Te) can be regarded as of antiperovskite structure with ordered vacancies and are demonstrated to be very promising candidates for X- and γ-ray semiconductor detectors. Depending on Q, the ordering of the Hg vacancies in these defect antiperovskites varies and yields a rich family of distinct crystal structures ranging from zero-dimensional to three-dimensional, with a dramatic effect on the properties of each compound. All three Hg3Q2I2 compounds show very suitable optical, electrical, and good mechanical properties required for radiation detection at room temperature. These compounds possess a high density (>7 g/cm3) and wide bandgaps (>1.9 eV), showing great stopping power for hard radiation and high intrinsic electrical resistivity, over 1011 Ω cm. Large single crystals are grown using the vapor transport method, and each material shows excellent photo sensitivity under energetic photons. Detectors made from thin Hg3Q2I2 crystals show reasonable response under a series of radiation sources, including 241Am and 57Co radiation. The dimensionality of Hg–Q motifs (in terms of ordering patterns of Hg vacancies) has a strong influence on the conduction band structure, which gives the quasi one-dimensional Hg3Se2I2 a more prominently dispersive conduction band structure and leads to a low electron effective mass (0.20 m0). For Hg3Se2I2 detectors, spectroscopic resolution is achieved for both 241Am α particles (5.49 MeV) and 241Am γ-rays (59.5 keV), with full widths at half-maximum (FWHM, in percentage) of 19% and 50%, respectively. The carrier mobility-lifetime μτ product for Hg3Q2I2 detectors is achieved as 10–5–10–6 cm2/V. The electron mobility for Hg3Se2I2 is estimated as 104 ± 12 cm2/(V·s). On the basis of these results, Hg3Se2I2 is the most promising for room-temperature radiation detection.

Publisher URL: http://dx.doi.org/10.1021/jacs.7b03174

DOI: 10.1021/jacs.7b03174

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.