Nanoscale Mapping of Strain and Composition in Quantum Dots Using Kelvin Probe Force Microscopy

• Published in: Nano letters 2007-07, Vol.7 (7), p.2089-2093
• Main Authors: Shusterman, S, Raizman, A, Sher, A, Paltiel, Y, Schwarzman, A, Lepkifker, E, Rosenwaks, Y
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Quantum dots; Surface double layers, schottky barriers, and work functions; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl071031w

A key factor in improving quantum dots electrical properties and dots-based devices is the ability to control the crucial parameters of composition, doping, size, and strain distribution of the dots. We show that nanometer-scale work function measurements using ultrahigh vacuum Kelvin probe force microscopy is capable of measuring the strain and composition variations within and around individual QDs. This is accomplished by analyzing the detailed surface potential profiles in and around InSb/GaAs dots.