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Title: An unusual crystal growth method of the chalcohalide semiconductor, β-Hg 3S 2Cl 2: A new candidate for hard radiation detection

Here, we assess the mercury chalcohalide compound, β-Hg 3S 2Cl 2, as a potential semiconductor material for X-ray and γ-ray detection. It has a high density (6.80 g/cm 3) and wide band gap (2.56 eV) and crystallizes in the cubic Pm4$$\bar{3}$$n space group with a three-dimensional structure comprised of [Hg 12S 8] cubes with Cl atoms located within and between the cubes, featuring a trigonal pyramidal SHg3 as the main building block. First-principle electronic structure calculations at the density functional theory level predict that the compound has closely lying indirect and direct band gaps. We have successfully grown transparent, single crystals of β-Hg 3S 2Cl 2 up to 7 mm diameter and 1 cm long using a new approach by the partial decomposition of the quaternary Hg 3Bi 2S 2Cl 8 compound followed by the formation of β-Hg 3S 2Cl 2 and an impermeable top layer, all happening in situ during vertical Bridgman growth. The decomposition process was optimized by varying peak temperatures and temperature gradients using a 2 mm/h translation rate of the Bridgman technique. Formation of the quaternary Hg 3Bi 2S 2Cl 8 followed by its partial decomposition into β-Hg 3S 2Cl 2 was confirmed by in situ temperature-dependent synchrotron powder diffraction studies. The single crystal samples obtained had resistivity of 10 10 Ω·cm and mobility-lifetime products of electron and hole carriers of 1.4(4) × 10 –4 cm 2/V and 7.5(3) × 10 –5 cm 2/V, respectively. Further, an appreciable Ag X-ray photoconductivity response was observed showing the potential of β-Hg 3S 2Cl 2 as a hard radiation detector material.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [3] ;  [2]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States); Northwestern Univ., Evanston, IL (United States)
  3. Northwestern Univ., Evanston, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Crystal Growth and Design
Additional Journal Information:
Journal Volume: 16; Journal Issue: 5; Journal ID: ISSN 1528-7483
Publisher:
American Chemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; Crystal growth; Mercury chalcohalide; Mobility-lifetime product; Semiconductor; X-ray detector; γ-ray Detector
OSTI Identifier:
1352554