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.

Emission and X ray diffraction in AlGaAs/ InGaAs Quantum wells with embedded InAs Quantum dots

2013 ◽  
Vol 1617 ◽  
pp. 43-48
Author(s):  
R. Cisneros Tamayo ◽  
I.J. Gerrero Moreno ◽  
A. Vivas Hernandez ◽  
J.L. Casas Espinola ◽  
L. Shcherbyna
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Thermal Annealing ◽  
Peak Position ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Prepared State ◽  
Temperature Dependences

ABSTRACTThe photoluminescence (PL), its temperature dependence and X-ray diffraction (XRD) have been studied in MBE grown GaAs/AlGaAs/InGaAs/AlGaAs /GaAs quantum wells (QWs) with InAs quantum dots embedded in the center of InGaAs layer in the freshly prepared states and after the thermal treatments during 2 hours at 640 or 710 °C. The structures contained two buffer (Al0.3Ga0.7As/In0.15Ga0.85As) and two capping (In0.15Ga0.85As / Al0.3Ga0.7As) layers. The temperature dependences of PL peak positions have been analyzed in the temperature range 10-500K with the aim to investigate the QD composition and its variation at thermal annealing. The experimental parameters of the temperature variation of PL peak position in the InAs QDs have been compared with the known one for the bulk InAs crystals and the QD composition variation due to Ga/Al/In inter diffusion at thermal treatments has been detected. XRD have been studied with the aim to estimate the capping/buffer layer compositions in the different QW layers in freshly prepared state and after the thermal annealing. The obtained emission and XRD data and their dependences on the thermal treatment have been analyzed and discussed.

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

InAs Quantum Dots Grown on an AlGaAsSb Strain-Relief Buffer

2000 ◽  
Vol 642 ◽  
Author(s):  
A.L. Gray ◽  
L. R. Dawson ◽  
Y. Lin ◽  
A. Stintz ◽  
Y.-C. Xin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cross Section ◽  
Gaas Substrate ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
X Ray Diffraction ◽  
Strain Relief ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Transmission Electron

ABSTRACTAn In(Ga)As-based self-assembled quantum dot laser test structure grown on strain-relief Al0.5Ga0.5As1-ySby strain-relief buffer layers (0≤y ≤ 0.24) on a GaAs substrate is investigated in an effort to increase dot size and therefore extend the emission wavelength over conventional InAs quantum dots on GaAs platforms. Cross-section transmission electron microscopy, and high-resolution x-ray diffraction are used to monitor the dislocation filtering process and morphology in the buffer layers. Results show that the buffer layers act as an efficient dislocation filter by drastically reducing threading dislocations, thus providing a relaxed, low dislocation, compositionally modulated Al0.5Ga0.5Sb0.24As0.76 substrate for large (500Å height x 300Å width) defect -free InAs quantum dots. Photoluminescence shows a ground-state emission of the InAs quantum dots at 1.45 μm.

scholarly journals High-Resolution X-Ray Diffraction Studies on MBE-Grown p-ZnTe/n-CdTe Heterojunctions for Solar Cell Applications

2014 ◽  
Vol 126 (5) ◽  
pp. 1083-1086
Author(s):  
K. Wichrowska ◽  
J.Z. Domagala ◽  
T. Wosinski ◽  
S. Chusnutdinow ◽  
G. Karczewski
Keyword(s):  
Solar Cell ◽  
High Resolution ◽  
X Ray Diffraction ◽  
X Ray

X-Ray diffraction analysis of multilayer InAs-GaAs heterostructures with InAs quantum dots

1999 ◽  
Vol 33 (11) ◽  
pp. 1229-1237 ◽  
Author(s):  
N. N. Faleev ◽  
A. Yu. Egorov ◽  
A. E. Zhukov ◽  
A. R. Kovsh ◽  
S. S. Mikhrin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
Inas Quantum Dots ◽  
X Ray

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

Optical And Structural properties of Vertical Aligned Self-Assembled InAs Quantum Dots Multilayers

2001 ◽  
Vol 676 ◽  
Author(s):  
J. C. González ◽  
M. I. N. da Silva ◽  
W. N. Rodrigues ◽  
F. M. Matinaga ◽  
R. Magalhaes-Paniago ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Structural Properties ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Self Assembled

ABSTRACTIn this work, we report optical and structural properties of vertical aligned self-assembled InAs quantum dots multilayers. The InAs quantum dots samples were grown by Molecular Beam Epitaxy. Employing Atomic Force Microscopy, Transmission Electron Microscopy, and Gracing Incident X-ray Diffraction we have studied the structural properties of samples with different number of periods of the multiplayer structure, as well as different InAs coverage. The optical properties were studied using Photoluminescence spectroscopy.

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