Dislocation structure and mobility in the layered semiconductor InSe: A first-principles study

TL;DR

This study uses first-principles calculations within a multiscale model to analyze dislocation structures and mobility in InSe, explaining its exceptional plasticity through stacking fault energetics.

Contribution

It introduces a material-specific multiscale approach to understand dislocation behavior in InSe based on first-principles data.

Findings

InSe exhibits low-energy stacking faults facilitating dislocation movement.

The model explains the microscopic origin of InSe's high plasticity.

Results align with recent experimental observations of InSe's plasticity.

Abstract

The structure and mobility of dislocations in the layered semiconductor InSe is studied within a multiscale approach based on generalized Peierls--Nabarro model with material-specific parametrization derived from first principles. The plasticity of InSe turns out to be attributed to peculiarities of the generalized stacking fault relief for the interlayer dislocation slips such as existence of the stacking fault with a very low energy and low energy barriers. Our results give a consistent microscopic explanation of recently observed [Science {\bf 369}, 542 (2020)] exceptional plasticity of InSe.