Issue 10, 2021

Group-IV(A) Janus dichalcogenide monolayers and their interfaces straddle gigantic shear and in-plane piezoelectricity

Abstract

Inversion symmetry in the 1T-phase of pristine dichalcogenide monolayer MX2 (M = Ge, Sn; X = S, Se) is broken in their Janus structures, MXY (M = Ge, Sn; X ≠ Y = S, Se), which induces an in-plane piezoelectric coefficient, d22 = 4.09 (2.15) pm V−1 and a shear piezoelectric coefficient, d15 = 7.90 (13.68) pm V−1 in the GeSSe (SnSSe) monolayer. High flexibility arising from the small Young's modulus (60–70 N m−1) found in these Group-IV(A) Janus monolayers makes them suitable for large-scale strain engineering. Application of 7% uniaxial tensile strain increases d22 and d15 colossally to 267.07 pm V−1 and 702.34 pm V−1, respectively, thereby reaching the level of bulk piezoelectric perovskite materials. When the Janus GeSSe monolayers are stacked to form a van der Waals (vdW) homo-bilayer, d22 lies between 19.87 and 73.26 pm V−1, while d15 falls into the range between 83.01 and 604.34 pm V−1, depending on the stacking order. The chalcogen exchange energies and overall stabilities of the monolayers and bilayers confirm the feasibility of their experimental synthesis. Moreover, hole mobility in the GeSSe monolayer is greater than the electron mobility along its zigzag directions (μe = 883 cm2 V−1 s−1 and μh = 1134 cm2 V−1 s−1). Therefore, the semiconducting, flexible, and piezoelectric Janus GeSSe monolayer and bilayers are immensely promising for futuristic applications in energy harvesting, nanopiezotronic field-effect transistors, atomically thin sensors, shear/torsion actuators, transducers, self-powered circuits in nanorobotics, and electromechanical memory devices, and biomedical and other nanoelectronic applications.

Graphical abstract: Group-IV(A) Janus dichalcogenide monolayers and their interfaces straddle gigantic shear and in-plane piezoelectricity

Supplementary files

Article information

Article type
Paper
Submitted
30 सितम्बर 2020
Accepted
12 फरवरी 2021
First published
12 फरवरी 2021

Nanoscale, 2021,13, 5460-5478

Group-IV(A) Janus dichalcogenide monolayers and their interfaces straddle gigantic shear and in-plane piezoelectricity

P. Nandi, A. Rawat, R. Ahammed, N. Jena and A. De Sarkar, Nanoscale, 2021, 13, 5460 DOI: 10.1039/D0NR07027K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements