Electronic states of InAs/GaAs quantum dots by scanning tunneling spectroscopy

Journal Article · Mon Sep 20 00:00:00 EDT 2010 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3491551· OSTI ID:21471004

Gaan, S; He, Guowei; Feenstra, R M ^[1]; Walker, J; Towe, E ^[2]

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1. Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
2. Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

InAs/GaAs quantum-dot (QD) heterostructures grown by molecular-beam epitaxy are studied using cross-sectional scanning tunneling microscopy and spectroscopy. Individual InAs QDs are resolved in the images. Tunneling spectra acquired 3-4 nm from the QDs show a peak located in the upper part of the GaAs band gap originating from the lowest electron confined state, together with a tail extending out from the valence band from hole confined states. A line-shape analysis is used to deduce the binding energies of the electron and hole QD states.

• OSTI ID: 21471004
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 12 Vol. 97; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL GROWTH METHODS
EPITAXY
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HETEROJUNCTIONS
HOLES
INDIUM ARSENIDES
INDIUM COMPOUNDS
MATERIALS
MICROSCOPY
MOLECULAR BEAM EPITAXY
NANOSTRUCTURES
PNICTIDES
QUANTUM DOTS
SCANNING TUNNELING MICROSCOPY
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
SOLID CLUSTERS
TUNNEL EFFECT
TUNNELING