Photoreflectance Investigation of Inas/Gaas Self-Assembled Quantum Dots Grown by Almbe

1999 ◽  
Vol 583 ◽  
Author(s):  
M. Geddol ◽  
R. Ferrinm ◽  
G. Guizzetti ◽  
M. Patrini ◽  
S. Franchi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ground State ◽  
Molecular Beam ◽  
State Transition ◽  
Transition Energy ◽  
Atomic Layer ◽  
Optical Response ◽  
Spectral Features ◽  
Modulation Spectroscopy ◽  
Self Assembled

AbstractPhotoreflectance measurements have been performed in the 0.8–1.5 eV photon energy range and at temperatures from 80 to 300 K on stacked layers of InAs/GaAs self-assembled quantum dots (QDs) grown by Atomic-Layer Molecular Beam Epitaxy. The spectral features due to the QD optical response were analyzed by using lineshape models characteristic of modulation spectroscopy of confined systems. The dependence of the ground state transition energy on the number of stacked QD layers is investigated and it is shown that Coulomb interaction can account for the observed different behavior of the ensemble optical response of QD families characterized by different morphologies and coexisting in the same sample.

scholarly journals Resonant photoluminescence and excitation spectroscopy of CdSe/ZnSe and CdTe/ZnTe self-assembled quantum dots

2002 ◽  
Vol 737 ◽  
Author(s):  
T. A. Nguyen ◽  
S. Mackowski ◽  
H. Rho ◽  
H. E. Jackson ◽  
L. M. Smith ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Excited State ◽  
Ground State ◽  
State Transition ◽  
Longitudinal Optical ◽  
Photoluminescence Spectra ◽  
Single Quantum Dots ◽  
Major Carrier ◽  
Excitation Mechanisms ◽  
Self Assembled

ABSTRACTWe show that two major carrier excitation mechanisms are present in II-VI self-assembled quantum dots. The first one is related to direct excited state – ground state transition. It manifests itself by the presence of sharp and intense lines in the excitation spectrum measured from single quantum dots. Apart from these lines, we also observe up to four much broader excitation lines. The energy spacing between these lines indicates that they are associated with absorption related to longitudinal optical phonons. By analyzing resonantly excited photoluminescence spectra, we are able to separate the contributions from these two mechanisms. In the case of CdTe dots, the excited state – ground state relaxation is important for all dots in ensemble, while phonon-assisted processes are dominant for the dots with smaller lateral size.

scholarly journals Temperature dependence of ultrasharp luminescence lines in AlyIn1−yAs/AlxGa1−xAs self-assembled quantum dots

1996 ◽  
Vol 74 (S1) ◽  
pp. 216-219 ◽  
Author(s):  
S. Raymond ◽  
S. Fafard ◽  
S. Charbonneau
Keyword(s):  
Quantum Dots ◽  
Ground State ◽  
State Transition ◽  
Thermionic Emission ◽  
Excitation Density ◽  
High Excitation ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Self Assembled ◽  
Intensity Evolution

Ensembles of~600 AlyIn1−yAs/AlxGa1−xAs self-assembled quantum dots (QDs) are investigated using photoluminescence (PL) and time-resolved PL in the visible. At very low excitation intensities, the PL spectrum shows multiple ultranarrow luminescence lines (FWHM ~200 μeV), which are attributed to the ground-state transition of a few dots (4 or less). The temperature and intensity evolution of these sharp lines is then monitored. The temperature-dependent measurements show that the line width and lifetime of the narrow lines remain constant up to the onset of thermionic, emission. Intensity-dependent measurements show that for high excitation density the collective background, emitted by the ensemble of QDs, is enhanced relative to the amplitude of individual ultranarrow lines.

scholarly journals Self‐assembled quantum dots of InSb grown on InP by atomic layer molecular beam epitaxy: Morphology and strain relaxation

1996 ◽  
Vol 69 (25) ◽  
pp. 3887-3889 ◽  
Author(s):  
J. C. Ferrer ◽  
F. Peiró ◽  
A. Cornet ◽  
J. R. Morante ◽  
T. Uztmeier ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Atomic Layer ◽  
Self Assembled

Thermal annealing effect on InAs/InGaAs quantum dots grown by atomic layer molecular beam epitaxy

2004 ◽  
Vol 269 (2-4) ◽  
pp. 181-186 ◽  
Author(s):  
G.X. Shi ◽  
P. Jin ◽  
B. Xu ◽  
C.M. Li ◽  
C.X. Cui ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Thermal Annealing ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Annealing Effect

Molecular beam epitaxial growth of InAs self-assembled quantum dots with light-emission at 1.3μm

2000 ◽  
Vol 208 (1-4) ◽  
pp. 93-99 ◽  
Author(s):  
Y Nakata ◽  
K Mukai ◽  
M Sugawara ◽  
K Ohtsubo ◽  
H Ishikawa ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Light Emission ◽  
Molecular Beam Epitaxial ◽  
Self Assembled ◽  
Molecular Beam Epitaxial Growth

InAs self-assembled quantum dots grown on an InP (311)B substrate by molecular beam epitaxy

2001 ◽  
Vol 89 (7) ◽  
pp. 4186-4188 ◽  
Author(s):  
Y. F. Li ◽  
J. Z. Wang ◽  
X. L. Ye ◽  
B. Xu ◽  
F. Q. Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Self Assembled

Self-assembled quantum dots and nanoholes by molecular beam epitaxial growth and atomically precise in situ etching

2002 ◽  
Vol 722 ◽  
Author(s):  
S. Kiravittaya ◽  
R. Songmuang ◽  
O. G. Schmidt
Keyword(s):  
Quantum Dots ◽  
Molecular Beam ◽  
Flat Surface ◽  
Local Strain ◽  
Growth Conditions ◽  
Etching Depth ◽  
Molecular Beam Epitaxial ◽  
Self Assembled ◽  
Molecular Beam Epitaxial Growth

AbstractEnsembles of homogeneous self-assembled quantum dots (QDs) and nanoholes are fabricated using molecular beam epitaxy in combination with atomically precise in situ etching. Self-assembled InAs QDs with height fluctuations of ±5% were grown using a very low indium growth rate on GaAs (001) substrate. If these dots are capped with GaAs at low temperature, strong room temperature emission at 1.3 νm with a linewidth of 21 meV from the islands is observed. Subsequently, we fabricate homogeneous arrays of nanoholes by in situ etching the GaAs surface of the capped InAs QDs with AsBr3. The depths of the nanoholes can be tuned over a range of 1-6 nm depending on the nominal etching depth and the initial capping layer thickness. We appoint the formation of nanoholes to a pronounced selectivity of the AsBr3 to local strain fields. The holes can be filled with InAs again such that an atomically flat surface is recovered. QDs in the second layer preferentially form at those sites, where the holes were initially created. Growth conditions for the second InAs layer can be chosen in such a way that lateral QD molecules form on a flat surface.

Assessing electronic states of InAsP/GaAs self-assembled quantum dots by photoluminescence and modulation spectroscopy

2019 ◽  
Vol 206 ◽  
pp. 639-644 ◽  
Author(s):  
Rafaela Moos ◽  
Igor Konieczniak ◽  
Graciely Elias dos Santos ◽  
Ângelo Luiz Gobbi ◽  
Ayrton André Bernussi ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electronic States ◽  
Modulation Spectroscopy ◽  
Self Assembled
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