Structure and Optical Properties of Hybrid-Layered-Double Perovskites (C8H20N2)2AgMBr8 (M = In, Sb, and Bi)

Hang Ruan; Zhongnan Guo; Jiawei Lin; Kunjie Liu; Lingling Guo; Xin Chen; Jing Zhao; Quanlin Liu; Wenxia Yuan

doi:10.1021/acs.inorgchem.1c01669

Structure and Optical Properties of Hybrid-Layered-Double Perovskites (C₈H₂₀N₂)₂AgMBr₈ (M = In, Sb, and Bi)

Inorg Chem. 2021 Oct 4;60(19):14629-14635. doi: 10.1021/acs.inorgchem.1c01669. Epub 2021 Sep 15.

Authors

Hang Ruan¹, Zhongnan Guo¹, Jiawei Lin¹, Kunjie Liu², Lingling Guo¹, Xin Chen³, Jing Zhao², Quanlin Liu², Wenxia Yuan¹

Affiliations

¹ Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
² The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
³ Beijing Advanced Innovation Center for Materials Genome Engineering, Institute of Solid State Chemistry, University of Science and Technology Beijing, Beijing 100083, China.

PMID: 34523334
DOI: 10.1021/acs.inorgchem.1c01669

Abstract

The Pb-free hybrid-layered-double perovskites (HLDPs) have been proposed as green and stable semiconducting materials for optoelectronic devices, but the synthesized members are still limited. Here, we report the synthesis of three new HLDPs, (C₈H₂₀N₂)₂AgMBr₈ (M = In, Sb, and Bi), by a solution method using 1,4-bis(ammoniomethyl)cyclohexane (C₈H₂₀N₂²⁺) as the organic spacing cation. All three of these HLDPs show ⟨100⟩-oriented layered structures with Ag and In/Sb/Bi order arranged in corner-sharing octahedral layers. The first-principle calculations indicate the indirect-gap nature of (C₈H₂₀N₂)₂AgInBr₈ and (C₈H₂₀N₂)₂AgSbBr₈, while their Bi counterpart shows a direct band gap after considering spin-orbit coupling. The band gaps obtained by diffuse-reflectance spectroscopy are 3.11, 2.60, and 2.70 eV for M = In, Sb, and Bi, respectively. (C₈H₂₀N₂)₂AgInBr₈ shows a broadband red emission centered at 690 nm, and it is mainly attributed to the self-trapped-excitons mechanism. Our results not only provide a series of new "Pb-free" HLDPs with chemical diversity but also help us to further understand the structure-property relationships of HLDP materials.