Syntheses, crystal Structures and electronic Structures of new metal chalcoiodides Bi{sub 2}CuSe{sub 3}I and Bi{sub 6}Cu{sub 3}S{sub 10}I

Journal Article · Mon Feb 15 00:00:00 EST 2016 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2015.09.030· OSTI ID:22577767

Liang, I-Chu ^[1]; Bilc, Daniel I. ^[2]; Manoli, Maria ^[3]; Chang, Wei-Yun; Lin, Wen-Fu ^[1]; Kyratsi, Theodora ^[3]; Hsu, Kuei-Fang ^[1]

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1. Department of Chemistry, and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan (China)
2. Department of Molecular & Biomolecular Physics, National Institute for Research & Development of Isotopic & Molecular Technologies, Cluj-Napoca 400293 (Romania)
3. Department of Mechanical and Manufacturing Engineering, University of Cyprus, 1678 Nicosia (Cyprus)

Two new metal chalcoiodides were synthesized by solid-state reactions at 400 °C. Crystal Data: Bi{sub 2}CuSe{sub 3}I, 1, monoclinic, C2/m, a=14.243(2) Å, b=4.1937(7) Å, c=14.647(2) Å, β=116.095(2)°, V=785.7(2) Å{sup 3}, and Z=4; Bi{sub 6}Cu{sub 3}S{sub 10}I, 2, orthorhombic, Pnma, a=17.476(2) Å, b=4.0078(4) Å, c=27.391(2) Å, V=1918.5(3) Å{sup 3}, and Z=4. Compound 1 adopts a three-dimensional structure formed by two alternative layers, which consist of BiSe{sub 5} square pyramids, BiSe{sub 4}I{sub 2} octahedra, CuSe{sub 4} tetrahedra, and CuSe{sub 2}I{sub 2} tetrahedra. Compound 2 possesses a new open framework built up of BiS{sub 5} square pyramides, BiS{sub 6} octahedra, BiS{sub 8} polyhedra, and CuS{sub 4} tetrahedra where I{sup −} anions are uniquely trapped within the tunnels. Both electronic structures reveal that bismuth and chalcogenide orbitals dominate the bandgaps. The Cu d and I p states contribute to the top of valence bands, in which the distribution of I orbitals may correspond to the relative bonding interactions in 1 and 2. The optical bandgaps determined by the diffuse reflectance spectra are 0.68 eV and 0.72 eV for 1 and 2, respectively. 1 is a p-type semiconductor with high Seebeck coefficients of 460–575 μV/K in the temperature range of 300–425 K. The electrical conductivity is 0.02 S/cm at 425 K for the undoped sample. The thermal conductivity is 0.22 W/mK at 425 K. - Graphical abstract: The hybridization of chalcogenides and iodides produces two new solids Bi2CuSe3I and Bi6Cu3S10I. The I{sup −} anions participate in distinct bonding interactions within the two structures and that is consistent with the analyses of density of states. 1 is a p-type semiconductor with an optical bandgap of 0.68 eV, which possesses high Seebeck coefficient and low lattice thermal conductivity in 300–425 K.

• OSTI ID: 22577767
• Journal Information: Journal of Solid State Chemistry, Vol. 234; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ANIONS
BISMUTH
BONDING
CRYSTALS
DENSITY
DENSITY OF STATES
ELECTRIC CONDUCTIVITY
ELECTRONIC STRUCTURE
HYBRIDIZATION
INTERACTIONS
IODIDES
LAYERS
MONOCLINIC LATTICES
ORTHORHOMBIC LATTICES
SOLIDS
SPECTRA
SYNTHESIS
TEMPERATURE RANGE
THERMAL CONDUCTIVITY