CsHgInS₃: a New Quaternary Semiconductor for γ-ray Detection

Abstract

The new layered compound CsHgInS 3 was synthesized using solid state and flux synthesis techniques. The compound is a semiconductor and shows promising properties for X-ray and γray detection. It features a layered structure that crystallizes in the monoclinic space group C2/c with cell parameters: a = 11.2499(7) Å ́, b = 11.2565(6) Å ́, c = 22.146(1) Å ́, β = 97.30(5)°, V = 2781.8(4) Å 3, and Z = 8. CsHgInS 3 is isostructural to Rb 2 Cu 2 Sn 2 S 6 , where the Hg, In, and Cs atoms occupy the Cu, Sn, and Rb sites, respectively. Large single crystals with dimension up to 5 mm were grown with a vertical Bridgman method as well as a horizontal traveling heater method. CsHgInS 3 has a γ-ray attenuation length comparable to commercial Cd 1−x Zn x Te and a band gap value of 2.30 eV. The electrical resistivity of CsHgInS 3 is anisotropic with values of 98 GΩ cm and 0.33 GΩ cm perpendicular and parallel to the (001) plane, respectively. The mobility-lifetime product (μτ) of electrons and holes estimated from photoconductivity measurements on the as-grown crystals were (μτ) e = 3.6 × 10 −5 cm 2 V −1 and (μτ) h = 2.9 × 10 −5 cm 2 V −1 , respectively. Electronic structure calculations at the Density Functional Theory level were performed based on the refined crystal structure of CsHgInS 3 and show a direct gap with the conduction band near the Fermi level being highly dispersive, suggesting a relatively small carrier effective mass for electrons.

TlHgInS3: An Indirect-Band-Gap Semiconductor with X-ray Photoconductivity Response

“…20,[38][39][40][41] Hg on the other hand adopts flexible coordination geometry from linear, trigonal planar, tetrahedral and even octahedral, resulting in diverse structure types. 5 have identified Tl 2 Hg 3 Q 4 (Q = S, Se, Te) as promising detector materials using the "dimensional reduction" approach, 10 and TlHg 6 Q 4 Br 5 (Q = S, Se) using the "lattice hybridization" approach. 39 Here we report a new Tl and Hg containing material, the indirect band gap semiconductor TlHgInS 3 .…”

Synthesis, Structure and Bonding, Optical Properties of Ba4MTrQ6 (M=Cu, Ag; Tr=Ga, In; Q=S, Se)

“…For example, ACd 5 Ga 4 S 12 (A = K, Rb, Cs) compounds adopt a noncentrosymmetric structure and exhibit interesting IR nonlinear optical thermochromic properties from 298 to 10 K. [28] CsHgInS 3 and CsCdInQ 3 (Q = Se, Te) are expected to be new photoconductive compounds as potential materials for hard radiation detection. [29,30] Furthermore, In 4 Pb x Sn y Se 3 is a promising candidate for mid-temperature thermoelectric materials with an excellent figure of merit (ZT) value of 1.4 at 733 K. [31,32] Although many mixed metal multi-chalcogenides have been reported, quaternary examples containing d 10 transition-metal ions such as Cu 1 + and Ag 1 + are rare. [33][34][35] It was reported that Cu I and Ag I ions tend to exhibit highly diversified and flexible coordination numbers with chalcogens.…”

“…For example, ACd 5 Ga 4 S 12 (A=K, Rb, Cs) compounds adopt a noncentrosymmetric structure and exhibit interesting IR nonlinear optical thermochromic properties from 298 to 10 K 28. CsHgInS 3 and CsCdInQ 3 (Q=Se, Te) are expected to be new photoconductive compounds as potential materials for hard radiation detection 29. 30 Furthermore, In 4 Pb x Sn y Se 3 is a promising candidate for mid‐temperature thermoelectric materials with an excellent figure of merit ( ZT ) value of 1.4 at 733 K 31.…”

The Phosphidosilicates SrSi7P10and BaSi7P10

“…The basic building units of these compounds are SiP 4 tetrahedra condensed by vertices to T2 supertetrahedra (Figure 2, yellow) according to the Yaghi [ 20 ] notation. By zigzag fusion of these entities, which was sparely observed in related compounds, [ 6,10–11,21–28 ] chains are formed, depicted in turquoise in Figure 2. Further vertex‐edge condensation of these fused T2‐chain motifs – to the best of our knowledge only once observed [ 29 ] – yields in T2 layers, which are propagating in the ab plane, visualized by condensation of the blue T2 chains in Figure 2.…”