63 research outputs found
Relevance of the purity level in a MetalOrganic Vapour Phase Epitaxy reactor environment for the growth of high quality pyramidal sitecontrolled Quantum Dots
We report in this work on the spectral purity of pyramidal site-controlled
InGaAs/AlGaAs Quantum Dots grown by metalorganic vapour phase epitaxy on(111)B
oriented GaAs substrates. Extremely sharp emission peaks were found, showing
linewidths surprisingly narrow (~27{\mu}eV) and comparable to those which can
be obtained by Molecular Beam Epitaxy in an ultra-high vacuum environment. A
careful reactor handling is regarded as a crucial step toward the fabrication
of high optical quality systems.Comment: ICMOVPE 2010 Proceedin
Semiconductor nanostructures engineering: Pyramidal quantum dots
Pyramidal quantum dots (QDs) grown in inverted recesses have demonstrated
over the years an extraordinary uniformity, high spectral purity and strong
design versatility. We discuss recent results, also in view of the
Stranski-Krastanow competition and give evidence for strong perspectives in
quantum information applications for this system. We examine the possibility of
generating entangled and indistinguishable photons, together with the need for
the implementation of a, regrettably still missing, strategy for electrical
control
A site-controlled quantum dot system offering both high uniformity and spectral purity
In this paper we report on the optical properties of site controlled InGaAs
dots with GaAs barriers grown in pyramidal recesses by metalorganic vapour
phase epitaxy. The inhomogeneous broadening of excitonic emission from an
ensemble of quantum dots is found to be unusually narrow, with a standard
deviation of 1.19 meV, and spectral purity of emission lines from individual
dots is found to be very high (18-30 ueV), in contrast with other
site-controlled systems.Comment: 12 pages, 3 figure
Impact of Nitrogen incorporation on pseudomorphic site-controlled quantum dots grown by Metalorganic Vapour Phase Epitaxy
We report on some surprising optical properties of diluted nitride
InGaAs_(1-y)N_y /GaAs (y<<1) pyramidal site-controlled quantum dots, grown by
metalorganic vapor phase epitaxy on patterned GaAs (111)B substrates.
Microphotoluminescence characterizations showed antibinding exciton/ biexciton
behavior, a spread of exciton lifetimes in an otherwise very uniform sample,
with unexpected long neutral exciton lifetimes (up to 7 ns) and a nearly zero
fine structure splitting on a majority of dots
Morphological, compositional, and geometrical transients of V-groove quantum wires formed during metalorganic vapor-phase epitaxy
We present a theoretical model of the formation of self-limited (Al) GaAs quantum wires within V-grooves on GaAs(001) substrates during metalorganic vapor-phase epitaxy. We identify the facet-dependent rates of the kinetic processes responsible for the formation of the self-limiting profile, which is accompanied by Ga segregation along the axis perpendicular to the bottom of the original template, and analyze their interplay with the facet geometry in the transient regime. A reduced model is adopted for the evolution of the patterned profile, as determined by the angle between the different crystallographic planes as a function of the growth conditions. Our results provide a comprehensive phenomenological understanding of the self-ordering mechanism on patterned surfaces which can be harnessed for designing the quantum optical properties of low-dimensional systems. (C) 2013 AIP Publishing LLC
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