Highly Anisotropic Electronic and Mechanical Properties of Monolayer and Bilayer As2S3

TL;DR

This study reveals that monolayer and bilayer As2S3 exhibit highly anisotropic electronic and mechanical properties, surpassing black phosphorus, with potential applications in flexible nanoelectronics and nanomechanics.

Contribution

First-principles calculations demonstrate the large anisotropic properties of As2S3 monolayer and bilayer, providing insights for future orientation-dependent nanoelectronic and nanomechanical devices.

Findings

Anisotropic Young's modulus factors of 3.15 and 3.32 for monolayer and bilayer As2S3.

As2S3's anisotropic properties exceed those of black phosphorus.

Potential for flexible, orientation-dependent nanoelectronic applications.

Abstract

Anisotropic materials, with orientation-dependent properties, have attracted more and more attention due to their compelling tunable and flexible performance in electronic and optomechanical devices. So far, two-dimensional (2D) black phosphorus shows the largest known anisotropic behavior, which is highly desired for synaptic and neuromorphic devices, multifunctional directional memories, and even polarization-sensitive photodetector, whereas it is unstable at ambient conditions. Recently, 2D few-layered As2S3 with superior chemical stability was successfully exfoliated in experiments. However, the electronic and mechanical properties of monolayer and bilayer As2S3 is still lacking. Here, we report the large anisotropic electronic and mechanical properties of As2S3 systems through first-principles calculations and general angle-dependent Hooke's law. Monolayer and bilayer As2S3 exhibit anisotropic factors of Young's modulus of 3.15 and 3.32, respectively, which are larger than the black phosphorous with experimentally confirmed and an anisotropic factor of 2. This study provides an effective route to flexible orientation-dependent nanoelectronics, nanomechanics, and offers implications in promoting related experimental investigations.