University of Oulu

Lu, L., Botella, R. and Cao, W. (2023), Theoretical Study of Stability of Halogen-Defective Trihalide Monolayers: Cases of AlI₃, AsI₃, and IrBr₃. Phys. Status Solidi B, 260: 2300001.

Theoretical study of stability of halogen-defective trihalide monolayers : cases of AlI₃, AsI₃, and IrBr₃

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Author: Lu, Leran1; Botella, Romain1; Cao, Wei1
Organizations: 1Faculty of Science, Nano and Molecular Systems Resesarch Unit, University of Oulu, Fin-90014 Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 2 MB)
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Language: English
Published: John Wiley & Sons, 2023
Publish Date: 2023-10-31


A theoretical study is conducted with three MX₃ monolayer 2D materials (AlI₃, AsI₃, and IrBr₃) on their electronic properties and how a halogen monovacancy affects their thermostability. Density functional theory (DFT) calculations are run to obtain the band structures and phonon dispersions for both pristine and defective structures. It is shown that AlI₃ and AsI₃ have indirect bandgaps of 2.40 and 2.23 eV, respectively. IrBr₃ has a direct bandgap of 1.65 eV. Phonon dispersions indicate that they are all thermodynamically stable in pristine state, but their defective counterparts are not. Ab-initio molecular dynamics (AIMD) simulations are conducted for defective ones to further investigate their stability. It is found that AlI₃ and AsI₃ layers are decomposed while IrBr3 layer is bent. Further investigations are conducted by analyzing the bond energies and bond lengths of the three materials. It shows that AlI₃ and AsI₃ have lower bond energy and longer bond length, which makes them dissociated at the ambient temperature while higher bond energy and shorter bond length keep IrBr₃ stabilized and enable its displacive phase transition in displacive limit.

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Series: Physica status solidi. B
ISSN: 0370-1972
ISSN-E: 1521-3951
ISSN-L: 0370-1972
Volume: 260
Issue: 9
Article number: 2300001
DOI: 10.1002/pssb.202300001
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
Funding: This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 101002219).
EU Grant Number: (101002219) CATCH - Cross-dimensional Activation of Two-Dimensional Semiconductors for Photocatalytic Heterojunctions
Copyright information: © 2023 The Authors. physica status solidi (b) basic solid state physics published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.