Electric field modulation on negative Poisson's ratio of Two-dimensional arsenic and antimony monolayers by first-principles calculation

TL;DR

This study uses first-principles calculations to demonstrate electric field control of negative Poisson's ratio in monolayer arsenic and antimony, revealing tunable auxetic properties for potential optoelectronic applications.

Contribution

It introduces the auxetic effect in Sb monolayers and shows how electric fields can significantly modulate their negative Poisson's ratio, a novel finding in 2D materials.

Findings

Monolayer Sb is phonon unstable, unlike As.

Out-of-plane NPR can be reversibly modulated by uniaxial strain.

Electric fields can alter NPR values by over 70% in As and 55% in Sb.

Abstract

We have introduced the auxetic effect in MBP-analog Sb for the first time, and achieve NPR modulations on monolayer As and Sb via first-principles calculation. Comparing with As, the monolayer Sb is phonon unstable. By applying an uniaxial strain along each directions, we discovered a zigzag-vertical reversibility on out-of-plane NPR, and the NPR values for monolayer As and Sb are simulated to be -0.125/-0.172 and -0.036/-0.063 by applying strain along zigzag/vertical directions. The NPR values could be significantly manipulated by applying vertical electrical fields, as increased up to 70.3% for monolayer As and decreased up to 55.6% for monolayer Sb. Such intrinsic NPR and electric field modulation could make those monolayers potential applications in auxetic optoelectronic devices, electrodes and sensors, leading to novel multi-functionalities.