Local structure of In_(0.5)Ga_(0.5)As from joint high-resolution and differential pair distribution function analysis

TL;DR

This study combines high-resolution total and indium differential atomic pair distribution functions to analyze local structural distortions in In_(0.5)Ga_(0.5)As alloys, revealing distinct In-As and Ga-As bond lengths.

Contribution

It introduces a joint analysis method using total and differential PDFs to quantify local lattice distortions in semiconductor alloys.

Findings

Resolved In-As and Ga-As bond length differences.

Quantified local lattice distortions in In_(0.5)Ga_(0.5)As.

Demonstrated the effectiveness of differential PDFs for chemical-specific structural analysis.

Abstract

High resolution total and indium differential atomic pair distribution functions (PDFs) for In_(0.5)Ga_(0.5)As alloys have been obtained by high energy and anomalous x-ray diffraction experiments, respectively. The first peak in the total PDF is resolved as a doublet due to the presence of two distinct bond lengths, In-As and Ga-As. The In differential PDF, which involves only atomic pairs containing In, yields chemical specific information and helps ease the structure data interpretation. Both PDFs have been fit with structure models and the way in that the underlying cubic zinc-blende lattice of In_(0.5)Ga_(0.5)As semiconductor alloy distorts locally to accommodate the distinct In-As and Ga-As bond lengths present has been quantified.