Tunability of Photoluminescence of InAs/GaAs Quantum Dots by Growth Pause Introduced Ripening

2008 ◽  
Vol 8 (12) ◽  
pp. 6232-6237
Author(s):  
N. Halder ◽  
S. Chakrabarti ◽  
C. R. Stanley
Keyword(s):  
Growth Rate ◽  
Quantum Dots ◽  
Growth Temperature ◽  
High Surface ◽  
High Growth ◽  
Blue Shift ◽  
Sufficient Time ◽  
Surface Mobility ◽  
Self Organized ◽  
Growth Pause

The effect of dot ripening pause on self organized InAs/GaAs QD's grown by MBE at two different growth rates and the resulting tunability of emission properties were studied with the help of PL and AFM experiments. We found the evolution of larger coherent islands with dot-pause due to high surface mobility of the In adatoms at the growth temperature resulting in a redshift in the PL spectra. A small blue shift in the emission is observed in case of the islands grown at higher growth rate and being allowed to ripen for sufficient time due to In desorption at high growth temperature.

Self-Organized ZnSe Quantum Dots: Synthesis and Characterization

2008 ◽  
Vol 8 (3) ◽  
pp. 1502-1511
Author(s):  
Diksha Kaushik ◽  
R. R. Singh ◽  
A. B. Sharma ◽  
D. Gupta ◽  
M. Sharma ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Tight Binding ◽  
Blue Shift ◽  
Luminescence Spectroscopy ◽  
Self Organized ◽  
Chemical Technique ◽  
Oxide Substrate ◽  
Indium Tin Oxide Substrate

Self-organized ZnSe quantum dots (Q-ZnSe) were grown on indium tin oxide substrate using wet chemical technique without or in presence of copper and manganese dopants. The structural, morphological and luminescence properties of the as grown Q-dot films have been investigated, using X-ray diffraction, transmission electron microscopy, atomic force microscopy and optical and luminescence spectroscopy. Composition of the samples were analyzed using atomic absorption spectroscopy. The quantum dots have been shown to deposit in a compact, uniform and organized array on the indium tin oxide substrate. The size dependent blue shift in the experimentally determined absorption edge has been compared with the theoretical predictions based on the effective mass and tight binding approximations. It is shown that the experimentally determined absorption edges depart significantly from the theoretically calculated values. The photoluminescence properties of the undoped as well as doped Q-ZnSe have also been discussed.

scholarly journals Dense lying self-organized GaAsSb quantum dots on GaAs for efficient lasers

2011 ◽  
Vol 2 ◽  
pp. 333-338 ◽  
Author(s):  
Thomas H Loeber ◽  
Dirk Hoffmann ◽  
Henning Fouckhardt
Keyword(s):  
Quantum Dots ◽  
Growth Temperature ◽  
Flux Ratio ◽  
Emission Wavelength ◽  
Research Groups ◽  
Pl Spectra ◽  
Self Organized ◽  
Electrically Pumped

GaAsSb quantum dots (QDs) were grown on GaAs in the Stranski–Krastanov (SK) epitaxial mode. Their characteristics were dependent on the Sb/Ga (V/III) flux ratio and the growth temperature. The samples were grown with a V/III ratio between 0.45/1 and 1.50/1 and a temperature between 445 and 580 °C, not commonly used by other research groups. These parameters enabled the growth of dense lying dots with a density at least up to 6.5 × 1010 cm−2 and a diameter and height of 20 and 4 nm, respectively. The photoluminescence (PL) spectra revealed a QD peak at an emission wavelength between λ = 0.876 and 1.035 μm, depending on the exact conditions. Using a stack of such QD layers, an electrically pumped efficient QD laser was realized with an emission wavelength of λ ≈ 0.900 µm at a temperature of 84 K.

Competing Kinetic and Thermodynamic Processes in the Growth and Ordering of Ga0.5In0.5P

1993 ◽  
Vol 312 ◽  
Author(s):  
Sarah R. Kurtz ◽  
J. M. Olson ◽  
D. J. Arent ◽  
A. E. Kibbler ◽  
K. A. Bertness
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Band Gap ◽  
Growth Temperature ◽  
Growth Parameter ◽  
High Growth ◽  
High Growth Rate ◽  
Temperature Growth ◽  
Rate Region ◽  
Thermodynamic Processes

AbstractThe band gap of Ga0.5In0.5P is studied as a function of growth temperature, growth rate, and substrate misorientation. As each of these parameters is independently varied the band gap first decreases, then increases, resulting in “U” shaped curves. Each “U” shaped curve shifts if any other growth parameter is varied. The data presented here can be divided into two regions of parameter space. In the low temperature, low substrate misorientation, high growth rate region, the band gap is shown to decrease with increasing growth temperature, decreasing growth rate, and increasing substrate misorientation. In the high temperature, high substrate misorientation, low growth rate region, the opposite trends are observed. The implications of these data on the ordering mechanism are discussed.

scholarly journals Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

2020 ◽  
Author(s):  
Dario Schiavon ◽  
Elżbieta Litwin-Staszewska ◽  
Rafał Jakieła ◽  
Szymon Grzanka ◽  
Piotr Perlin
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Low Temperature ◽  
Surface Morphology ◽  
Growth Temperature ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Pit Formation ◽  
Movpe Growth

The effect of growth temperature and precursor flows on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

Tem Investigation of Self-Organized Pbse Quantum Dots as a Function of Spacer Layer Thickness and Growth Temperature

1999 ◽  
Vol 583 ◽  
Author(s):  
H. H. Kang ◽  
L. Salamanca-Riba ◽  
M. Pinczolits ◽  
G. Springholz ◽  
V. Holy ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Layer Thickness ◽  
Spatial Correlation ◽  
Growth Temperature ◽  
Stacking Sequence ◽  
Self Organized ◽  
Spacer Layer Thickness ◽  
Spacer Layer ◽  
Spacer Thickness ◽  
Vertical Correlation

AbstractThe study of the morphology, lateral and vertical correlation of self-organized PbSe quantum dots in Pb1−xEux Te is presented. The samples consist of quantum dot superlattices of n periods of (PbSe/Pb1−xEux Te) grown on PbTe/(111) BaF2 by the S-K mode using MBE. The Pb1−xEux Te spacer thickness was varied from 34.3nm to 312nm and the growth temperature was varied between 335°C and 380°C. Our TEM results show very good lateral and vertical correlation of the dots. The dots form an array with either a/b/c/a/b/c/... or a/a/a/... vertical stacking sequence along the [111] growth direction. The stacking sequence is accurately controlled by the thickness of the Pb1−xEux Te spacer layer thickness and the growth temperature. The best a/b/c/... spatial correlation was obtained for temperatures around 380°C and spacer thickness of ˜40nm. The dots are highly strained and form triangular pyramids with (111) bases and (100) facets as observed by AFM. The shape of the dots also varied with the Pb1−xEux Te spacer thickness. An analysis of the spatial correlation of the dots' size and shape with respect to spacer thickness and growth temperature is presented.

Growth Temperature Dependence of Size Distribution of Selfassembled Inas Quantum Dots on Gaas(001): From Diffusion- to Strain-Limited Growth

1999 ◽  
Vol 583 ◽  
Author(s):  
J. Yuan ◽  
G. D. Lian ◽  
Z. Y. Li ◽  
D. A. Ritchie ◽  
R. M. Thompson ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Size Distribution ◽  
Growth Temperature ◽  
High Growth ◽  
Misfit Strain ◽  
Diffusion Limited Aggregation ◽  
Mbe Growth ◽  
Inas Quantum Dots ◽  
Transmission Electron ◽  
Geometric Size

AbstractWe have investigated the molecular beam epitaxy (MBE) growth of buried InAs quantum dots on GaAs (001) surface, as a function of deposition temperature, by transmission electron microscopy (TEM) and photoluminescence (PL). We found that the dot growth at low temperature is controlled by diffusion-limited aggregation. As the growth temperature increases, this growth mode is modified by misfit strain, resulting in a narrowing of the size distribution. However, we did not find any evidence for a thermodynamically optimized size. In addition, we found that the optical properties of the quantum dots does not correlate directly with the geometric size of the quantum dots, indicating a complex internal structure for quantum dots grown at high growth temperature.

Saturated dot density of InAs∕GaAs self-assembled quantum dots grown at high growth rate

2007 ◽  
Vol 90 (16) ◽  
pp. 161906 ◽  
Author(s):  
C. K. Chia ◽  
Y. W. Zhang ◽  
S. S. Wong ◽  
A. M. Yong ◽  
S. Y. Chow ◽  
...  
Keyword(s):  
Growth Rate ◽  
Quantum Dots ◽  
High Growth ◽  
High Growth Rate ◽  
Self Assembled ◽  
Dot Density

Testing the upper limit of InAs/GaAs self-organized quantum dots density by fast growth rate

2008 ◽  
Vol 44 (4-5) ◽  
pp. 420-424 ◽  
Author(s):  
C.K. Chia ◽  
Y.W. Zhang ◽  
S.S. Wong ◽  
S.J. Chua ◽  
A.M. Yong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Quantum Dots ◽  
Fast Growth ◽  
Self Organized ◽  
Upper Limit ◽  
Fast Growth Rate

Epitaxial Growth of 4H-SiС Using Si2(CH3)6+Si2Cl6+C3H8+H2 System by Atmospheric Pressure Hot CVD Method

2012 ◽  
Vol 717-720 ◽  
pp. 97-100
Author(s):  
Hyun Seung Lee ◽  
Min Jae Kim ◽  
Min Hee Kim ◽  
Sang Il Lee ◽  
Won Jae Lee ◽  
...  
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Gas Phase ◽  
Growth Temperature ◽  
Atmospheric Pressure ◽  
High Growth ◽  
High Growth Rate ◽  
High Quality ◽  
Cvd Method

The chlorinated precursor is recently focused for high growth rate and high quality epitaxial layer. In the previous studies, the addition of chlorinated species from Si2Cl6 in the gas phase eliminated simultaneous Si nucleation which interferes with epitaxy. In this work, the characterization of epitaxial layers grown with chlorinated species is focused. High growth rate of 30 μm/h was achieved by using Si2(CH3)6 and Si2Cl6 as chlorinated precursors. We concluded that high growth rate was achieved by using HMDS and HCDS as the precursor of SiC at growth temperature of 1600 °C.

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