Coupled Effects in Quantum Dot Nanostructures with Nonlinear Strain and Bridging Modelling Scales

TL;DR

This paper introduces a coupled Schrödinger-Poisson model that incorporates nonlinear strain effects and piezoelectric contributions, highlighting their importance in accurately analyzing the optoelectromechanical properties of quantum dot nanostructures.

Contribution

It presents a generalized coupled model for bandstructure calculations that includes nonlinear strain and piezoelectric effects, advancing beyond traditional linear, uncoupled approaches.

Findings

Piezoelectric effects are crucial and must be included in models.

Nonlinear strain terms significantly influence bandstructure analysis.

Fully coupled models provide more accurate insights into nanostructure properties.

Abstract

We demonstrate that the conventional application of linear models to the analysis of optoelectromechanical properties of nanostructures in bandstructure engineering could be inadequate. The focus of the present paper is on a model based on the coupled Schrodinger-Poisson system where we account consistently for the piezoelectric effect and analyze the influence of different nonlinear terms in strain components. The examples given in this paper show that the piezoelectric effect contributions are essential and have to be accounted for with fully coupled models. While in structural applications of piezoelectric materials at larger scales, the minimization of the full electromechanical energy is now a routine in many engineering applications, in bandstructure engineering conventional approaches are still based on linear models with minimization of uncoupled, purely elastic energy functionals with respect to displacements. Generalizations of the existing models for bandstructure calculations are presented in this paper in the context of coupled effects.