scholarly journals Vertical composition gradient in InGaAs∕GaAs alloy quantum dots as revealed by high-resolution x-ray diffraction

2004 ◽  
Vol 85 (15) ◽  
pp. 3062-3064 ◽  
Author(s):  
M. Hanke ◽  
D. Grigoriev ◽  
M. Schmidbauer ◽  
P. Schäfer ◽  
R. Köhler ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
Composition Gradient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Quantum Dots

scholarly journals Formation of ZnO/Zn0.5Cd0.5Se Alloy Quantum Dots in the Presence of High Oleylamine Contents

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 999
Author(s):  
Yi-An Chen ◽  
Kuo-Hsien Chou ◽  
Yi-Yang Kuo ◽  
Cheng-Ye Wu ◽  
Po-Wen Hsiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Particle Size ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Average Size ◽  
Alloy Quantum Dots ◽  
First Time

To the best of our knowledge, this report presents, for the first time, the schematic of the possible chemical reaction for a one-pot synthesis of Zn0.5Cd0.5Se alloy quantum dots (QDs) in the presence of low/high oleylamine (OLA) contents. For high OLA contents, high-resolution transmission electron microscopy (HRTEM) results showed that the average size of Zn0.5Cd0.5Se increases significantly from 4 to 9 nm with an increasing OLA content from 4 to 10 mL. First, [Zn(OAc)2]–OLA complex can be formed by a reaction between Zn(OAc)2 and OLA. Then, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) data confirmed that ZnO is formed by thermal decomposition of the [Zn(OAc)2]–OLA complex. The results indicated that ZnO grew on the Zn0.5Cd0.5Se surface, thus increasing the particle size. For low OLA contents, HRTEM images were used to estimate the average sizes of the Zn0.5Cd0.5Se alloy QDs, which were approximately 8, 6, and 4 nm with OLA loadings of 0, 2, and 4 mL, respectively. We found that Zn(OAc)2 and OLA could form a [Zn(OAc)2]–OLA complex, which inhibited the growth of the Zn0.5Cd0.5Se alloy QDs, due to the decreasing reaction between Zn(oleic acid)2 and Se2−, which led to a decrease in particle size.

Elastic strains in quantum dots studied by high resolution X-ray diffraction

1996 ◽  
Vol 40 (1-8) ◽  
pp. 373-377 ◽  
Author(s):  
V Holy ◽  
A.A Darhuber ◽  
G Bauer ◽  
P.D Wang ◽  
Y.P Song ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elastic Strains

Lateral and vertical ordering in multilayered self-organized InGaAs quantum dots studied by high resolution x-ray diffraction

1997 ◽  
Vol 70 (8) ◽  
pp. 955-957 ◽  
Author(s):  
A. A. Darhuber ◽  
V. Holy ◽  
J. Stangl ◽  
G. Bauer ◽  
A. Krost ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Organized

High Resolution X-Ray Diffraction and Reflectivity Studies of Vertical and Lateral Ordering in Multiple Self-Organized InGaAs Quantum Dots

1997 ◽  
Vol 36 (Part 1, No. 6B) ◽  
pp. 4084-4087 ◽  
Author(s):  
Anton A. Darhuber ◽  
Vaclav Holy ◽  
Julian Stangl ◽  
Günther Bauer ◽  
Alois Krost ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Organized ◽  
Lateral Ordering

In enrichment in (In,Ga)As/GaAs quantum dots studied by high-resolution x-ray diffraction and pole figure analysis

1999 ◽  
Vol 75 (19) ◽  
pp. 2957-2959 ◽  
Author(s):  
A. Krost ◽  
J. Bläsing ◽  
F. Heinrichsdorff ◽  
D. Bimberg
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
Pole Figure ◽  
X Ray Diffraction ◽  
X Ray

Influence of quantum-dots density on average in-plane strain of optoelectronic devices investigated by high-resolution X-ray diffraction

2009 ◽  
Vol 206 (8) ◽  
pp. 1714-1717
Author(s):  
Raul O. Freitas ◽  
Beatriz Diaz ◽  
Eduardo Abramof ◽  
Alain A. Quivy ◽  
Sérgio L. Morelhão
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
Plane Strain ◽  
Optoelectronic Devices ◽  
X Ray Diffraction ◽  
X Ray

Temperature Dependent Characterization of Imbedded InAs Quantum Dots in GaAs Superlattice Solar Cell Structures by High Resolution X-ray Diffraction

2012 ◽  
Vol 1432 ◽  
Author(s):  
Josephine J. Sheng ◽  
David. C. Chapman ◽  
David M. Wilt ◽  
Stephen J. Polly ◽  
Christopher G. Bailey ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Solar Cell ◽  
High Resolution ◽  
Nanostructured Materials ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Cell Structures

ABSTRACTThe insertion of nanostructured materials (such as quantum wells, wires, and dots) into the intrinsic region of p-i-n solar cells introduces an intermediate band within the bandgap of the host material. It has been shown that the sub-bandgap conversion provided by the nanostructured materials, enhances the short circuit current as well as the overall efficiency of InAs quantum dots (QD) imbedded in GaAs superlattice (SL) solar cells [1]. As a contender for space applications, it is necessary to subject these solar cell structures to temperatures encountered in the Low Earth Orbit (LEO), probing for any material degradation. Herein, we focus on temperature dependent characterization using high resolution X-ray diffraction (HRXRD) of InAs QD enhanced GaAs solar cell structures with varying growth parameters. The structures characterized can be classified into three groups: (1) GaP strain compensation coverage, (2) GaAs barrier coverage, and (3) InAs coverage for QD formation. HRXRD rocking curves of each structure focusing around the GaAs peak are analyzed at a range of temperatures up to 200˚C. Although no noticeable shifts in the SL peaks are detected, interfacial diffusion decreased the resolution of fringes produced by reflections at the SL interfaces in test structures with varying InAs QD coverage. Unbalanced strain in the same structures shows a distortion in the GaAs peaks.

Lateral and vertical ordering of self-assembled PbSe quantum dots studied by high-resolution X-ray diffraction

2000 ◽  
Vol 283 (1-3) ◽  
pp. 65-68 ◽  
Author(s):  
V. Holý ◽  
J. Stangl ◽  
G. Springholz ◽  
M. Pinczolits ◽  
G. Bauer ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Resolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembled

Effects of Rapid Thermal Annealing on the Intersubband Energy Spacing of Self-Assembled InAs/Gaas Quantum Dots

1999 ◽  
Vol 588 ◽  
Author(s):  
X. C. Wang ◽  
S. J. Chua ◽  
S. J. Xu ◽  
Z. H. Zhang
Keyword(s):  
Quantum Dots ◽  
Excited State ◽  
High Resolution ◽  
Thermal Treatment ◽  
Ground State ◽  
Infrared Detectors ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembled

AbstractIn this paper, we showed the significant reduction of the energy spacing between ground state and excited state emissions from InAs/GaAs quantum dots due to interface interdiffusion induced by thermal treatment. In addition, the strong narrowing of the luminescence linewidth of the ground state and excited state emissions from the InAs dot layers for the annealed samples indicates an improvement of the size-distribution of the QDs. Large blue-shift of the energy positions of both emissions was also observed. High resolution X-Ray diffraction experiments give strong evidence of the interface atom interdiffusion in the annealed samples. This work shows ability to tune the wavelength for applications like infrared detectors and lasers based on intrasubband transitions of self-assembled QDs.

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