Correlation lengths in stacked InAs quantum dot systems studied by cross-sectional scanning tunnelling microscopy

Summary, in English

We have studied the influence of the InP spacer layer thickness on stacked InAs/InP quantum dots, using cross-sectional scanning tunnelling microscopy. We show that for a spacer layer thickness of up to 30 nm, the quantum dots are spatially correlated but for a separating distance of 50 nm the vertical ordering of the dots is lost. These values are the same as previously found for quantum dots in the InAs/GaAs system despite the large difference in lattice mismatch between the InAs/GaAs ( 7%) and InAs/InP ( 3%) systems. We show that the apparent similarities can be understood by a combination of intermixing in the dots and differences in dot size. Finally, we demonstrate that the size of the quantum dots is affected by their vertical correlation.

• Author: Lassana Ouattara; J. M. Ulloa; Anders Mikkelsen; Edvin Lundgren; P. M. Koenraad; Magnus Borgström; Lars Samuelson; Werner Seifert
• Department/s: Synchrotron Radiation Research; Solid State Physics
• Publishing year: 2007
• Language: English
• Publication/Series: Nanotechnology
• Volume: 18
• Issue: 14
• Links: http://dx.doi.org/10.1088/0957-4484/18/14/145403
• Document type: Journal article
• Publisher: IOP Publishing
• Topic: Nano Technology
• Status: Published
• ISBN/ISSN/Other: ISSN: 0957-4484