Origin of non-linear piezoelectricity in III-V semiconductors: Internal strain and bond ionicity from hybrid-functional density functional theory

TL;DR

This study uses hybrid-functional density functional theory to analyze the origins of non-linear piezoelectricity in III-V semiconductors, highlighting the roles of internal strain and bond ionicity in these effects.

Contribution

It provides a first-principles derivation of piezoelectric coefficients and introduces a phenomenological model linking internal strain, charge centers, and ionicity effects.

Findings

Non-linear piezoelectric effects are significant in III-V semiconductors.

Internal strain and charge redistribution critically influence piezoelectric response.

The balance between ionic and electronic contributions explains the magnitude of non-linear effects.

Abstract

We derive first- and second-order piezoelectric coefficients for the zinc-blende III-V semiconductors, {Al,Ga,In}-{N,P,As,Sb}. The results are obtained within the Heyd-Scuseria-Ernzerhof hybrid-functional approach in the framework of density functional theory and the Berry-phase theory of electric polarization. To achieve a meaningful interpretation of the results, we build an intuitive phenomenological model based on the description of internal strain and the dynamics of the electronic charge centers. We discuss in detail first- and second-order internal strain effects, together with strain-induced changes in ionicity. This analysis reveals that the relatively large importance in the III-Vs of non-linear piezoelectric effects compared to the linear ones arises because of a delicate balance between the ionic polarization contribution due to internal strain relaxation effects, and the contribution due to the electronic charge redistribution induced by macroscopic and internal strain.