Strain distribution in zincblende and wurtzite nanowires bent by a one-sided stressor shell

Description

Abstract

We present a finite-strain model capable of describing the large deformations in bent nanowire heterostructures. The electromechanical model incorporates an energy functional that effectively captures the lattice-mismatch-induced strain and piezoelectric fields. We use the finite element method to solve the resulting partial differential system and extract cross-sectional maps of the full strain tensor for zincblende and wurtzite nanowires with lattice-mismatched core and one-sided stressor shell. In either case, the axial strain exclusively determines the bending. However, the distinct difference in shear strain has important consequences with regard to both the mechanical deformation and the existence of transverse piezoelectric fields in the nanowires. This is particularly significant as the strain has the potential to influence the electronic band structure and the dynamics of charge carriers.