Quantitative strain analysis of InAs/GaAs quantum dot materials

• Main Authors: Vullum, Per Erik, Nord, Magnus, Vatanparast, Maryam, Thomassen, Sedsel Fretheim, Boothroyd, Chris, Holmestad, Randi, Fimland, Bjørn-Ove, Reenaas, Turid Worren
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2018
• Subjects: Quantum Dots; Quantitative Strain Analysis; DRNTU::Engineering::Materials
• Online Access: https://hdl.handle.net/10356/88146; http://hdl.handle.net/10220/45649
• Institution: Nanyang Technological University

Geometric phase analysis has been applied to high resolution aberration corrected (scanning) transmission electron microscopy images of InAs/GaAs quantum dot (QD) materials. We show quantitatively how the lattice mismatch induced strain varies on the atomic scale and tetragonally distorts the lattice in a wide region that extends several nm into the GaAs spacer layer below and above the QDs. Finally, we show how V-shaped dislocations originating at the QD/GaAs interface efficiently remove most of the lattice mismatch induced tetragonal distortions in and around the QD.