Synthesis, Structure, and Optical Properties of Antiperovskite-Derived Ba2MQ3X (M = As, Sb; Q = S, Se; X = Cl, Br, I) Chalcohalides

Ruiqi Wang; Xian Zhang; Jianqiao He; Kejun Bu; Chong Zheng; Jianhua Lin; Fuqiang Huang

doi:10.1021/acs.inorgchem.7b02812

Synthesis, Structure, and Optical Properties of Antiperovskite-Derived Ba₂MQ₃X (M = As, Sb; Q = S, Se; X = Cl, Br, I) Chalcohalides

Inorg Chem. 2018 Feb 5;57(3):1449-1454. doi: 10.1021/acs.inorgchem.7b02812. Epub 2018 Jan 8.

Authors

Ruiqi Wang¹, Xian Zhang¹, Jianqiao He², Kejun Bu², Chong Zheng³, Jianhua Lin¹, Fuqiang Huang^{1

2}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
² CAS Key Laboratory of Materials for Energy Conversion and State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics , Chinese Academy of Sciences , Shanghai 200050, People's Republic of China.
³ Department of Chemistry and Biochemistry, Northern Illinois University , DeKalb, Illinois 60115, United States.

PMID: 29309131
DOI: 10.1021/acs.inorgchem.7b02812

Abstract

Six isostructural antiperovskite-derived chalcohalides, Ba₂MQ₃X (M = As, Sb; Q = S, Se; X = Cl, Br, I), crystallizing in the space group Pnma, have been synthesized by solid-state reactions. The crystal structure features a 3D framework with the [XBa₅]⁹⁺ disordered square pyramids as building blocks and [MQ₃]^3- units filling the interspace. [XBa₅]⁹⁺ disordered square pyramids are edge-sharing along [010], derived from the fusing of the two pyramids in octahedral [XBa₆]¹¹⁺. Surprisingly, Ba₂AsS₃X (X = Cl, Br, I) show almost the same optical band gap of 2.80 eV, and Ba₂AsSe₃X (X = Br, I) also have a similar band gap of 2.28 eV. The optical band gap of Ba₂SbS₃I is 2.64 eV. First-principles calculations reveal that the optical absorption is attributed to the transitions between Q np at the valence band maximum (VBM) and M np-Q np at the conduction band minimum (CBM). These compounds also possess interesting photoluminescence properties with splitting emission peaks on excitation at 200 nm.