Mapping of Axial Strain in InAs/InSb Heterostructured Nanowires

TL;DR

This study maps residual axial strain in InAs/InSb heterostructured nanowires using Raman and electron diffraction, revealing strain distribution and lattice mismatch effects.

Contribution

It provides the first detailed spatial mapping of residual strain along InAs/InSb nanowires using combined Raman and electron diffraction techniques.

Findings

Maximum strain at the interface

Strain relaxes towards nanowire tip

Lattice mismatch causes residual strain

Abstract

The article presents a mapping of the residual strain along the axis of InAs/InSb heterostructured nanowires. Using confocal Raman measurements, we observe a gradual shift in the TO phonon mode along the axis of these nanowires. We attribute the observed TO phonon shift to a residual strain arising from the InAs/InSb lattice mismatch. We find that the strain is maximum at the interface and then monotonically relaxes towards the tip of the nanowires. We also analyze the crystal structure of the InSb segment through selected area electron diffraction measurements and electron diffraction tomography on individual nanowires.