Title: An unusual crystal growth method of the chalcohalide semiconductor, β-Hg₃S₂Cl₂: A new candidate for hard radiation detection

Abstract

Here, we assess the mercury chalcohalide compound, β-Hg₃S₂Cl₂, as a potential semiconductor material for X-ray and γ-ray detection. It has a high density (6.80 g/cm³) 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 [Hg₁₂S₈] 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-Hg₃S₂Cl₂ up to 7 mm diameter and 1 cm long using a new approach by the partial decomposition of the quaternary Hg₃Bi₂S₂Cl₈ compound followed by the formation of β-Hg₃S₂Cl₂ 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 Hg₃Bi₂S₂Cl₈ followed by its partial decomposition into β-Hg₃S₂Cl₂ was confirmed by in situ temperature-dependent synchrotron powder diffraction studies. The single crystal samples obtained had resistivity of 10¹⁰ Ω·cm and mobility-lifetime products of electron and hole carriers of 1.4(4) × 10^–4 cm²/V and 7.5(3) × 10^–5 cm²/V, respectively. Further, an appreciable Ag X-ray photoconductivity response was observed showing the potential of β-Hg₃S₂Cl₂ as a hard radiation detector material.

Authors:

Wibowo, Arief C. ^[1]; Malliakas, Christos D. ^[2]; Li, Hao ^[1]; Stoumpos, Constantinos C. ^[1]; Chung, Duck Young ^[1]; Wessels, Bruce W. ^[3]; Freeman, Arthur J. ^[3]; Kanatzidis, Mercouri G. ^[2]

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+ Show Author Affiliations

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:

Wed Mar 16 00:00:00 EDT 2016

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation

OSTI Identifier:

1352554

Grant/Contract Number:  

AC02-06CH11357

Resource 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

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