Electronic and Thermoelectric Properties of Layered Oxychalcogenides (BiO)Cu Ch ( Ch = S, Se, Te)

Shibghatullah Muhammady; Yudhi Kurniawan; Seiya Ishiwata; Awabaikeli Rousuli; Toshiki Nagasaki; Shogo Nakamura; Hitoshi Sato; Atsushi Higashiya; Atsushi Yamasaki; Yoshiaki Hara; Andrivo Rusydi; Kouichi Takase; Yudi Darma

doi:10.1021/acs.inorgchem.8b01396

Electronic and Thermoelectric Properties of Layered Oxychalcogenides (BiO)Cu Ch ( Ch = S, Se, Te)

Inorg Chem. 2018 Aug 20;57(16):10214-10223. doi: 10.1021/acs.inorgchem.8b01396. Epub 2018 Aug 8.

Authors

Affiliations

¹ Department of Physics, Faculty of Mathematics and Natural Science , Institut Teknologi Bandung , Bandung 40132 , Indonesia.
² College of Sciences and Technology , Nihon University , Chiyoda , Tokyo 101-0062 , Japan.
³ Graduate School of Science , Hiroshima University , Kagamiyama 1-3-1 , Higashi-Hiroshima 739-8526 , Japan.
⁴ Faculty of Science , Hiroshima University , Kagamiyama 1-3-1 , Higashi-Hiroshima 739-8526 , Japan.
⁵ Hiroshima Synchrotron Radiation Center , Hiroshima University , Kagamiyama 2-313 , Higashi-Hiroshima 739-0046 , Japan.
⁶ Faculty of Science and Engineering , Setsunan University , Neyagawa , Osaka 572-8508 , Japan.
⁷ Faculty of Science and Engineering , Konan University , Kobe 658-8501 , Japan.
⁸ National Institute of Technology, Ibaraki College , Ibaraki 312-8508 , Japan.
⁹ NUSNNI-NanoCore, Department of Physics , National University of Singapore , Singapore 117411.
¹⁰ Singapore Synchrotron Light Source , National University of Singapore , Singapore 117603.

PMID: 30088921
DOI: 10.1021/acs.inorgchem.8b01396

Abstract

We study the new details of electronic and thermoelectric properties of polycrystalline layered oxychalcogenide systems of (BiO)Cu Ch ( Ch = Se, Te) prepared by using a solid-state reaction. The systems were characterized by using photoemission (PE) spectroscopy and four-probe temperature-dependent electrical resistivity ρ( T). PE spectra are explained by calculating the electronic properties using the generalized-gradient approximation method. PE spectra and ρ( T) show that (BiO)CuSe system is a semiconductor, while (BiO)CuTe system exhibits the metallic behavior that induces the high thermoelectric performance. The calculation of electronic properties of (BiO)Cu Ch ( Ch = S, Se, Te) confirms that the metallic behavior of (BiO)CuTe system is mainly induced by Te 5p states at Fermi energy level, while the indirect bandgaps of 0.68 and 0.40 eV are obtained for (BiO)CuS and (BiO)CuSe systems, respectively. It is also shown that the local symmetry distortion at Cu site strongly stimulates Cu 3d-t_2g to be partially hybridized with Ch p orbitals. This study presents the essential properties of the inorganic systems for novel functional device applications.