Shape Transition in Self-Organized InAs/InP Nanostructures

2001 ◽  
Vol 707 ◽  
Author(s):  
H.R. Gutiérrez ◽  
M.A. Cotta ◽  
M.M.G. de Carvalho
Keyword(s):  
Quantum Dots ◽  
Driving Force ◽  
Anisotropic Diffusion ◽  
Chemical Potential ◽  
Quantum Wires ◽  
Shape Transition ◽  
Self Organized ◽  
Self Assembled ◽  
Inp Substrates ◽  
Stable Shape

ABSTRACTIn this letter we report the transition from self-assembled InAs quantum-wires to quantum-dots grown on (100) InP substrates. This transition is obtained when the wires are annealed at the growth temperature. Our results suggest that the quantum-wires are a metastable shape originated from the anisotropic diffusion over the InP buffer layer during the formation of the first InAs monolayer. The wires evolve to a more stable shape (dot) during the annealing. The driving force for the transition is associated with variations in the elastic energy and hence in the chemical potential produced by height fluctuations along the wire. The regions along the wires with no height variations are more stable allowing the formation of complex, self-assembled nanostructures such as dots interconnected by wires.

Shape Transition in Self-Organized InAs/InP Nanostructures

2001 ◽  
Vol 696 ◽  
Author(s):  
H.R. Gutiérrez ◽  
M.A. Cotta ◽  
M.M.G. de Carvalho
Keyword(s):  
Growth Temperature ◽  
Driving Force ◽  
Anisotropic Diffusion ◽  
Chemical Potential ◽  
Quantum Wires ◽  
Shape Transition ◽  
Self Organized ◽  
Self Assembled ◽  
Inp Substrates ◽  
Stable Shape

AbstractIn this letter we report the transition from self-assembled InAs quantum-wires to quantumdots grown on (100) InP substrates. This transition is obtained when the wires are annealed at the growth temperature. Our results suggest that the quantum-wires are a metastable shape originated from the anisotropic diffusion over the InP buffer layer during the formation of the first InAs monolayer. The wires evolve to a more stable shape (dot) during the annealing. The driving force for the transition is associated with variations in the elastic energy and hence in the chemical potential produced by height fluctuations along the wire. The regions along the wires with no height variations are more stable allowing the formation of complex, self-assembled nanostructures such as dots interconnected by wires.

Microstructures and Growth Characteristics of Self-Assembled InAs/GaAs Quantum Dots Investigated by Transmission Electron Microscopy

2007 ◽  
Vol 26-28 ◽  
pp. 1207-1210
Author(s):  
Hyung Seok Kim ◽  
Ju Hyung Suh ◽  
Chan Gyung Park ◽  
Sang Jun Lee ◽  
Sam Kyu Noh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Chemical Potential ◽  
Early Stage ◽  
Compressive Strain ◽  
Potential Gradient ◽  
Growth Direction ◽  
Transmission Electron ◽  
Self Assembled

The microstructure and strain characteristics of self-assembled InAs/GaAs quantum dots (QDs) were studied by using transmission electron microscopy. Compressive strain was induced to uncapped QDs from GaAs substrate and the misfit strain largely increased after the deposition of GaAs cap layer. Tensile strain outside QD was extended along the vertical growth direction; up to 15 nm above the wetting layer. Vertically nonaligned and aligned stacked QDs were grown by adjusting the thickness of GaAs spacer layers. The QDs with a lens-shaped morphology were formed in the early stage of growth, and their apex was flattened by the out-diffusion of In atoms upon GaAs capping. However, aligned QDs maintained their lens-shaped structure with round apex after capping. It is believed that their apex did not flatten because the chemical potential gradient of In was relatively low due to the adjacent InAs QD layers.

Formation of quantum wires and quantum dots on buffer layers grown on InP substrates

2003 ◽  
Vol 255 (3-4) ◽  
pp. 266-272 ◽  
Author(s):  
A Stintz ◽  
T.J Rotter ◽  
K.J Malloy
Keyword(s):  
Quantum Dots ◽  
Quantum Wires ◽  
Buffer Layers ◽  
Inp Substrates

scholarly journals Shape transition of self-assembled InAs quantum dots onGaAs(114)A

2005 ◽  
Vol 71 (7) ◽  
Author(s):  
M. C. Xu ◽  
Y. Temko ◽  
T. Suzuki ◽  
K. Jacobi
Keyword(s):  
Quantum Dots ◽  
Shape Transition ◽  
Inas Quantum Dots ◽  
Self Assembled

scholarly journals Self Assembly of semiconductor nanostructures

Respuestas ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 47-51
Author(s):  
Máximo López-López ◽  
Esteban Cruz-Hernández ◽  
Isaac Martínez-Velis ◽  
Juan Salvador Rojas-Ramírez ◽  
Manolo Ramirez-Lopez ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam Epitaxy ◽  
Self Assembly ◽  
Molecular Beam ◽  
Quantum Wires ◽  
Preferential Growth ◽  
Growth Method ◽  
Strong Surface ◽  
Self Assembled

 Abstract In this work we present the growth and characterization of GaAs self-assembled quantum wires (SAQWRs), and InAs self-assembled quantum dots (SAQDs) by molecular beam epitaxy on (631)-oriented GaAs substrates. Adatoms on the (631) crystal plane present a strong surface diffusion anisotropy which we use to induce preferential growth along one direction to produce SAQWRs. On the other hand, InAs SAQDs were obtained on GaAs(631) with SAQWRs by the Stransky–Krastanov (S-K) growth method. SAQDs grown directly on (631) substrates presented considerable fluctuations in size. We study the effects of growing a stressor layer before the SAQDs formation to reduce these fluctuations.Keywords : Quantum wires, quantum dots; selfassembly; molecular beam epitaxy.

Optical properties of self-assembled ternary In(GAAl)As quantum dots on and B InP substrates

2000 ◽  
Vol 8 (2) ◽  
pp. 164-169
Author(s):  
Sun Zhong-Zhe ◽  
Liu Feng-Qi ◽  
Wu Ju ◽  
Ye Xiao-Ling ◽  
Ding Ding ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Self Assembled ◽  
Inp Substrates

Metamorphosis of self-organized quantum dots into quantum wires

1998 ◽  
Vol 249 (5-6) ◽  
pp. 555-559 ◽  
Author(s):  
Feng-Qi Liu ◽  
Zhan-Guo Wang ◽  
Bo Xu ◽  
Ju Wu ◽  
Jia-Jun Qian
Keyword(s):  
Quantum Dots ◽  
Quantum Wires ◽  
Self Organized

Self-assembled InAsSb quantum dots on (001) InP substrates

2004 ◽  
Vol 84 (9) ◽  
pp. 1510-1512 ◽  
Author(s):  
Yueming Qiu ◽  
David Uhl
Keyword(s):  
Quantum Dots ◽  
Self Assembled ◽  
Inp Substrates

Highly Tensile-Strained Self-Assembled Ge Quantum Dots on InP Substrates for Integrated Light Sources

2021 ◽  
Author(s):  
Qimiao Chen ◽  
Liyao Zhang ◽  
Yuxin Song ◽  
Xiren Chen ◽  
Sebastian Koelling ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Sources ◽  
Ge Quantum Dots ◽  
Self Assembled ◽  
Inp Substrates

scholarly journals Cathodoluminescence Wavelength Imaging Study of Clustering in InAs/GaAs Self-Assembled Quantum Dots

2000 ◽  
Vol 618 ◽  
Author(s):  
D. H. Rich ◽  
C. Zhang ◽  
I. Mukhametzhanov ◽  
A. Madhukar
Keyword(s):  
Quantum Dots ◽  
Spatial Scale ◽  
Size Distribution ◽  
Imaging Study ◽  
Island Growth ◽  
Spectral Lineshape ◽  
Force Microscopy ◽  
Self Organized ◽  
Atomic Force ◽  
Self Assembled

ABSTRACTCathodoluminescence wavelength imaging (CLWI) of InAs/GaAs self-assembled quantum dots (SAQDs) was performed to study the spatial variation in the spectral lineshape of the broadened quantum dot (QD) ensemble. The lineshape was found to vary on a scale of ∼μm, revealing attendant variations in the size distribution of SAQD clusters on this spatial scale. Energy variations in clusters of SAQDs are found to exhibit a spatial correlation with the efficiency of luminescence and the activation energy for thermal re-emission of carriers. A reduction in the energy variation of the QD clusters occurs when the thickness of the spacer layers in vertically self-organized samples is reduced or the number of stacks is increased. SAQDs were also prepared by punctuated island growth (PIG), in which deposition of the total desired amount is broken into two or more stages each separated by time delays. CLWI reveals a reduced variation in the energy of the dominant CL emission on a ∼μm spatial scale, correlating with a narrower size distribution of larger QDs for PIG, as measured in atomic force microscopy.

Sign in / Sign up

Export Citation Format

Share Document