Prediction of intrinsic ferroelectricity and large piezoelectricity in monolayer arsenic chalcogenides

Abstract

Two-dimensional materials that exhibit spontaneous electric polarization are of notable interest for functional materials. However, despite many two-dimensional polar materials are predicted in theory, the number of experimentally confirmed two-dimensional ferroelectrics are still far less than bulk ferroelectrics. We provide strong evidence that the Pmn2${}_1$ phase of arsenic chalcogenides As${}_2$X${}_3$ (X=S, Se, and Te), which include the recently isolated monolayer orpiment, are intrinsic ferroelectrics and demonstrate strong in-plane piezoelectricity. We found the calculated energy barriers for collectively reversing the electric polarization or moving a 180${}^{\circ }$ domain wall are reasonable compared to previously reported ferroelectrics. We propose a high-symmetry structure (with Pmmn space group) transforms into the ferroelectric Pmn2${}_1$ phase by a soft B${}_{2u}$ phonon mode. By studying other soft modes of the high-symmetry Pmmn structure, we identify several undiscovered metastable polymorphs, including a polar phase (with a P2${}_1$ space group) with sizable piezoelectricity.

References in corpus (13)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Superior mechanical flexibility of phosphorene and few-layer black phosphorus
• Out-of-plane Piezoelectricity and Ferroelectricity in Layered $\alpha$-In2Se3 Nano-flakes
• Pathways Towards Ferroelectricity in Hafnia
• Purely in-plane ferroelectricity in monolayer SnS at room temperature
• Ferroelectricity in ultra-thin perovskite films
• Mechanical Properties of Single-Layer Black Phosphorus
• Microscopic manipulation of ferroelectric domains in SnSe monolayers at room temperature
• Tuning the ferro- to para-electric transition temperature and dipole orientation of group-IV monochalcogenide monolayers
• Bulk and Two-dimensional Silver and Copper Monohalides: A Unique Class of Materials with Modest Ionicity/Covalency and Ferroelasticity/Multiferroicity
• Domain walls and ferroelectric reversal in corundum derivatives

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