Abstract
Geometric phase analysis (GPA), a fast and simple Fourier space method for strain analysis, can give useful information on accumulated strain and defect propagation in multiple layers of InAs/GaAs quantum dot (QD) materials. In this work, GPA has been applied to both high-resolution transmission electron microscopy (HRTEM) and high angular annular dark field scanning transmission electron microscopy (HAADF STEM) images. Strain maps determined from these images have been compared to each other, in order to analyze and assess the GPA technique in terms of accuracy. Ways to improve STEM data to get more reliable results are discussed.