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Title: Influence of strain and dislocations on GaSb/GaAs quantum dots: From nested to staggered band alignment

We investigate the influence of strain and dislocations on band alignment in GaSb/GaAs quantum dot systems. Composition profiles from cross-sectional scanning tunneling microscopy images are interpolated onto a finite element mesh in order to calculate the distribution of local elastic strain, which is converted to a spatially varying band alignment using deformation potential theory. Our calculations predict that dislocation-induced strain relaxation and charging lead to significant local variations in band alignment. Furthermore, misfit strain induces a transition from a nested (type I) to a staggered (type II) band alignment. Although dislocation-induced strain relaxation prevents the type I to type II transition, electrostatic charging at dislocations induces the staggered band alignment once again.

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Publisher / Repository:
American Institute of Physics
Date Published:
Journal Name:
Journal of Applied Physics
Page Range / eLocation ID:
Article No. 085703
Medium: X
Sponsoring Org:
National Science Foundation
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