Journal Article

FZJ-2020-02709

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Sub-Angstrom Characterization of the Structural Origin for High In-Plane Anisotropy in 2D GeS 2

Wang, X. ; Tan, J. ; Han, C. ; Wang, J.-J. (Corresponding author) ; Lu, L. ; Du, H.FZJ* ; Jia, C.-L.FZJ* ; Deringer, V. L. ; Zhou, J. ; Zhang, W.

2020
Soc. Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/25625  doi:10.1021/acsnano.9b10057

Abstract: Materials with layered crystal structures and high in-plane anisotropy, such as black phosphorus, present unique properties and thus promise for applications in electronic and photonic devices. Recently, the layered structures of GeS2 and GeSe2 were utilized for high-performance polarization-sensitive photodetection in the short wavelength region due to their high in-plane optical anisotropy and wide band gap. The highly complex, low-symmetric (monoclinic) crystal structures are at the origin of the high in-plane optical anisotropy, but the structural nature of the corresponding nanostructures remains to be fully understood. Here, we present an atomic-scale characterization of monoclinic GeS2 nanostructures and quantify the in-plane structural anisotropy at the sub-angstrom level in real space by Cs-corrected scanning transmission electron microscopy. We elucidate the origin of this high in-plane anisotropy in terms of ordered and disordered arrangement of [GeS4] tetrahedra in GeS2 monolayers, through density functional theory (DFT) calculations and orbital-based bonding analyses. We also demonstrate high in-plane mechanical, electronic, and optical anisotropies in monolayer GeS2 and envision phase transitions under uniaxial strain that could potentially be exploited for nonvolatile memory applications.

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Contributing Institute(s):

1. Physik Nanoskaliger Systeme (ER-C-1)

Research Program(s):

1. 143 - Controlling Configuration-Based Phenomena (POF3-143) (POF3-143)
2. DFG project 167917811 - SFB 917: Resistiv schaltende Chalkogenide für zukünftige Elektronikanwendungen: Struktur, Kinetik und Bauelementskalierung "Nanoswitches" (167917811) (167917811)

Appears in the scientific report 2020

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF >= 10 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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