Strain, size and composition of InAs Quantum Sticks, embedded in InP, by means of Grazing Incidence X-ray Anomalous Diffraction

TL;DR

This study employs grazing incidence x-ray anomalous diffraction to determine the structure, size, composition, and strain of InAs quantum sticks embedded in InP, providing detailed nanoscale insights.

Contribution

It introduces a method combining anomalous diffraction and finite difference calculations to analyze quantum stick structures and their strain and composition.

Findings

Average height of quantum sticks is 2.54 nm.

InAs quantum sticks exhibit 6.1% out-of-plane deformation.

Chemical mixing at interfaces is limited to at most 1 monolayer.

Abstract

We have used x-ray anomalous diffraction to extract the x-ray structure factor of InAs quantum stick-like islands, embedded in InP. The average height of the quantum sticks (QSs), as deduced from the width of the structure factor profile is 2.54nm. The InAs out of plane deformation, relative to InP, is equal to 6.1%. Diffraction Anomalous Fine Structure provides a clear evidence of pure InAs QSs. Finite Difference Method calculations reproduce well the diffraction data, and give the strain along the growth direction. Chemical mixing at interfaces is at most of 1ML