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Ultrahigh vacuum scanning tunnelling microscopy studies of the decapped InAs quantum dots on GaAs(001) surface after desorption of a protective As layer
Author(s) -
Bolotov L. N.,
Nakamura A.,
Evtikhiev V. P.,
Tokranov V. E.,
Titkov A. N.
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199905/06)27:5/6<533::aid-sia532>3.0.co;2-1
Subject(s) - wetting layer , band bending , quantum dot , scanning tunneling microscope , quantum tunnelling , materials science , annealing (glass) , spectroscopy , microscopy , layer (electronics) , optoelectronics , desorption , analytical chemistry (journal) , chemistry , nanotechnology , optics , composite material , adsorption , physics , organic chemistry , quantum mechanics , chromatography
Abstract The morphology and electronic properties of InAs quantum dots(QDs) on the GaAs(001) surface has been studiedby ultrahigh vacuum scanning tunnelling microscopy/spectroscopyafter removal of a preliminary deposited protective As layer. Athermal annealing procedure has been developed, which, applied to asample with an As cap layer, allows InAs QDs to be opened on thesurface of an InAs wetting layer (WL) exhibiting a[2×4] reconstruction of As dimers. Scanningtunnelling spectroscopy measurements on the decapped surface showthat I – V characteristics taken with themicroscope tip positioned over single InAs QDs have a smaller voltagewidth for zero conductivity (d I /d V =0) when compared with those taken over the InAs WL,which are essential the same as the I – V characteristics for a clean GaAs surface. This observation seems toindicate a weakening of the surface band bending in the areas beneathInAs QDs. Copyright © 1999 John Wiley & Sons, Ltd.