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Title: Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots

Authors:
; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Center for Solar and Thermal Energy Conversion (CSTEC)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1383972
DOE Contract Number:
SC0000957
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 3; Related Information: CSTEC partners with University of Michigan (lead); Kent State University
Country of Publication:
United States
Language:
English
Subject:
solar (photovoltaic), solar (thermal), phonons, thermal conductivity, thermoelectric, electrodes - solar, defects, charge transport, materials and chemistry by design, optics, synthesis (novel materials), synthesis (self-assembly)

Citation Formats

Huang, S., Kim, S. J., Pan, X. Q., and Goldman, R. S.. Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots. United States: N. p., 2014. Web. doi:10.1063/1.4891330.
Huang, S., Kim, S. J., Pan, X. Q., & Goldman, R. S.. Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots. United States. doi:10.1063/1.4891330.
Huang, S., Kim, S. J., Pan, X. Q., and Goldman, R. S.. Mon . "Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots". United States. doi:10.1063/1.4891330.
@article{osti_1383972,
title = {Origins of interlayer formation and misfit dislocation displacement in the vicinity of InAs/GaAs quantum dots},
author = {Huang, S. and Kim, S. J. and Pan, X. Q. and Goldman, R. S.},
abstractNote = {},
doi = {10.1063/1.4891330},
journal = {Applied Physics Letters},
number = 3,
volume = 105,
place = {United States},
year = {Mon Jul 21 00:00:00 EDT 2014},
month = {Mon Jul 21 00:00:00 EDT 2014}
}
  • We have examined the origins of interlayer formation and misfit dislocation (MD) displacement in the vicinity of InAs/GaAs quantum dots (QDs). For QDs formed by the Stranski-Krastanov mode, regularly spaced MDs nucleate at the interface between the QD and the GaAs buffer layer. In the droplet epitaxy case, both In island formation and In-induced “nano-drilling” of the GaAs buffer layer are observed during In deposition. Upon annealing under As flux, the In islands are converted to InAs QDs, with an InGaAs interlayer at the QD/buffer interface. Meanwhile, MDs nucleate at the QD/interlayer interface.
  • InAs/GaAs quantum dots (QD's) are formed by postgrowth annealing of an InAs wetting layer thinner than the critical thickness for the transition from two- (2D) to three-dimensional (3D) growth mode. Reflection high energy electron diffraction is used to monitor the QD formation. Based on a mean-field theory [Phys. Rev. Lett. 79, 897 (1997)], the time evolution of total QD's volume, first increasing and finally saturating, is well explained by precursors forming during wetting layer growth and converting into nucleated QD's after growth stop. Both the saturation QD's volume and the QD nucleation rate depend exponentially on the InAs coverage. Thesemore » behaviors and their temperature and InAs growth rate dependences are essentially understandable in the frame of the mean-field theory. Similar analysis to conventional QD growth suggests that the often observed significant mass transport from wetting layer to QD's can be ascribed to the precursors existing before 2D-3D growth mode transition.« less
  • The authors report on the use of GaAs islands, formed by the droplet epitaxy growth technique, as a template for the growth of clusters of InAs quantum dots. Surface morphology measurements show that the shape and dimensions of the GaAs islands and consequently the formation of InAs quantum dots depend strongly on the annealing temperature and annealing time. This can be explained by the diffusion of gallium atom during the annealing process and the selective formation of InAs quantum dots on the misoriented GaAs island sidewalls.
  • The distribution of hydrostatic strains in Bi{sup 3+}-doped InAs quantum dots embedded in a GaAs matrix are calculated in the context of the deformation-potential model. The dependences of strains in the material of spherical InAs quantum dots with substitutional (Bi {yields} As) and interstitial (Bi) impurities on the quantum-dot size are derived. The qualitative correlation of the model with the experiment is discussed. The data on the effect of doping on the morphology of self-assembled InAs:Bi quantum dots in a GaAs matrix are obtained.