Converse Flexoelectricity in van der Waals (vdW) Three-Dimensional Topological Insulator Nanoflakes

verfasst von

Qiong Liu, Srivilliputtur Subbiah Nanthakumar, Bin Li, Teresa Cheng, Florian Bittner, Chenxi Ma, Fei Ding, Lei Zheng, Bernhard Roth, Xiaoying Zhuang

Abstract

Low-dimensional van der Waals (vdW) three-dimensional (3D) topological insulators (TIs) have been overlooked, regarding their electromechanical properties. In this study, we experimentally investigate the electromechanical coupling of low-dimensional 3D TIs with a centrosymmetric crystal structure, where a binary compound, bismuth selenide (Bi₂Se₃), is taken as an example. Piezoresponse force microscopy (PFM) results of Bi₂Se₃ nanoflakes show that the material exhibits both out-of-plane and in-plane electromechanical responses. With careful analyses, the electromechanical responses are verified to arise from the converse flexoelectricity. The Bi₂Se₃ nanoflakes have a decreasing effective out-of-plane piezoelectric coefficient d₃₃^eff with the thickness increasing, with the d₃₃^eff value of ∼0.65 pm V^-1 for the 37 nm-thick sample. The measured effective out-of-plane piezoelectric coefficient is mainly contributed by the flexoelectric coefficient, μ₃₉, which is estimated to be approximately 0.13 nC m^-1. The results can help to understand the flexoelectricity of low-dimensional vdW TIs with centrosymmetric crystal structures, which is crucial for the design of nanoelectromechanical devices and spintronics built by vdW TIs.

Organisationseinheit(en)

Fakultät für Mathematik und Physik
Institut für Kunststoff- und Kreislauftechnik
Institut für Festkörperphysik
Angewandte Photonik - Optische Analytik, Sensorik und Spektroskopie
PhoenixD: Simulation, Fabrikation und Anwendung optischer Systeme
Hannoversches Zentrum für Optische Technologien (HOT)

Externe Organisation(en)

Tongji University

Typ

Artikel

Journal

Journal of Physical Chemistry C

Band

128

Seiten

16265-16273

Anzahl der Seiten

9

ISSN

1932-7447

Publikationsdatum

26.09.2024

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Energie (insg.), Physikalische und Theoretische Chemie, Oberflächen, Beschichtungen und Folien

Elektronische Version(en)

https://doi.org/10.1021/acs.jpcc.4c05690 (Zugang: Offen)