THE INFLUENCE OF ENVIRONMENTAL EFFECTS ON THE ACOUSTIC PHONON SPECTRA IN QUANTUM-DOT HETEROSTRUCTURES

2002 ◽  
Vol 12 (04) ◽  
pp. 1147-1158 ◽  
Author(s):  
SALVADOR RUFO ◽  
MITRA DUTTA ◽  
MICHAEL A. STROSCIO
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Environmental Effects ◽  
Phonon Spectrum ◽  
Acoustic Phonon ◽  
Matrix Material ◽  
Free Standing ◽  
Phonon Spectra ◽  
The Matrix ◽  
Selection Of

We present calculations of the acoustic phonon spectra for a variety of quantum dots and consider the cases where the quantum dots are both free-standing and embedded in a selection of different matrix materials — including semiconductors, plastic, and water. These results go beyond previous calculations for free-standing quantum dots and demonstrate that the matrix material can have a large effect on the acoustic phonon spectrum and consequently on a variety of phonon-assisted transitions in quantum-dot heterostructures.

Application of Finite Difference Method in Modeling Quantum Dot Superlattice Silicon Tandem Solar Cell

2014 ◽  
Vol 898 ◽  
pp. 249-252 ◽  
Author(s):  
Jie Huang ◽  
Jian Liang Jiang ◽  
Abdelkader Sabeur
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Quantum Dot ◽  
Difference Method ◽  
Matrix Material ◽  
Three Dimensional ◽  
Tandem Solar Cell ◽  
The Matrix

In this paper we propose an effective method to model quantum dot superlattice silicon tandem solar cell. The Schrödinger equation is solved through finite difference method (FDM) to calculate energy band of three-dimensional silicon quantum dots embedded in the matrix of SiO2 and Si3N4.We simulate the quantum dot superlattice as regularly spaced array of equally sized cubic dots in respective matrix. For simplicity, we consider only one period of the structure in calculation. From the result, the effects of matrix material, dot size and inter-dot distance on the bandgap are obtained.

Plasma Spraying of Self-Lubricating Cr2O3-CaF2 Coatings

1997 ◽  
Author(s):  
F. Vos ◽  
L. Delaey ◽  
M. De Bonte ◽  
L. Froyen
Keyword(s):  
Plasma Spraying ◽  
Matrix Material ◽  
Production Method ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
The Matrix ◽  
Preparation Step ◽  
Plasma Sprayed ◽  
The Relationship ◽  
Selection Of

Abstract Results are presented of a project analysing the relationship between the production parameters of plasma sprayed self-lubricating Cr2O3-CaF2 coatings and their structural, wear and lubricating properties. The production method consists of a preparation step where a powder blend of the matrix material (Cr203) and solid lubricant (CaF2) is agglomerated, followed by atmospheric plasma spraying (APS) of the agglomerates. Selection of the most appropriate agglomeration and plasma spray parameters as well as the microstructure of the coatings will be discussed.

Initial Stages of InAs Quantum Dots Evolution in GaAs/AlAs Matrixes

2002 ◽  
Vol 749 ◽  
Author(s):  
Michael Yakimov ◽  
Vadim Tokranov ◽  
Alex Katnelson ◽  
Serge Oktyabrsky
Keyword(s):  
Quantum Dots ◽  
Direct Evidence ◽  
Matrix Material ◽  
Single Layer ◽  
High Energy ◽  
Inas Quantum Dots ◽  
Auger Signal ◽  
The Matrix ◽  
Growth Evolution

ABSTRACTWe have studied the first phases of post-growth evolution of InAs quantum dots (QDs) using in-situ Auger electron spectroscopy in conjunction with Reflection High Energy Electron Diffraction (RHEED). Direct evidence for InAs intermixing with about 6ML (monolayers) of the matrix material is found from Auger signal behavior during MBE overgrowth of InAs nanostructures. Re-establishment of 2D growth mode by overgrowth with GaAs or AlAs was monitored in single-layer and multi-layer QD structures using RHEED. Decay process of InAs QDs on the surface is found to have activation energy of about 1.1 eV that corresponds to In intermixing with the matrix rather than evaporation from the surface.

Elements and Materials Improve the FDM Products: A Review

2016 ◽  
Vol 16 ◽  
pp. 33-51 ◽  
Author(s):  
Abduladim Salem Bala ◽  
Saidin bin Wahab ◽  
Mazatusziha binti Ahmad
Keyword(s):  
Matrix Material ◽  
Process Parameter ◽  
Correct Selection ◽  
Complex Environment ◽  
Technology Process ◽  
The Matrix ◽  
Additive Materials ◽  
Insight Into ◽  
Selection Of

This work aims to provide a review of available published literature that explores the opportunities to improve the quality of fused deposit modelling (FDM) products, particularly in medical applications. The paper presents details concerning the basis of the technology, process parameter settings and their responses, and reviews the properties of common FDM engineering/bio-materials and the available methods applied for improving their performance. Based on the researches which have been reviewed, FDM technology works within a complex environment from process parameters. Thus, it can achieve good results only with the proper settings for these parameters according to the properties of the material used. Improving the polymers is essentially based on the correct selection of additive materials, which can particularly enhance the key property/properties in the matrix material. This review provides a brief insight into FDM technology, provides an idea of the process parameter settings, the available materials and ways of modifying their properties to consequently improve the quality of FDM products.

scholarly journals Two-colour Three-pulse Spectrally Resolved Nonlinear Spectroscopy for Studies of Dynamics in Semiconductor Si Quantum Dots

2020 ◽  
Vol 30 (1) ◽  
pp. 79
Author(s):  
Vuong Van Cuong ◽  
Dinh Ba Khuong ◽  
Dao Van Lap
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Optical Phonon ◽  
Acoustic Phonon ◽  
Nonlinear Spectroscopy ◽  
Transverse Optical ◽  
Transverse Acoustic ◽  
Spectrally Resolved ◽  
Si Quantum Dots

We demonstrate that a two-colour three-pulsenonlinear spectroscopy can be used to study the dynamics of excited carriers inSi quantum dot structures embedded in SiN. Decays of the transverse optical phonon population and the transverse acoustic phonon population are measured and discussed. A simple theoretical modelis also used to support interpretation of our experimental observations.

Three-qubit PHASE gate in lateral quantum dots: Influence of the acoustic phonon and quantum-dot configuration

2009 ◽  
Vol 80 (2) ◽  
Author(s):  
Song Yang ◽  
Ming Gong ◽  
Chuanfeng Li ◽  
Cheng Zhao ◽  
Xubo Zou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Acoustic Phonon ◽  
Phase Gate

Modeling of Phonon Dispersion in a Semiconductor Quantum Dot Crystal

2002 ◽  
Vol 731 ◽  
Author(s):  
Olga L. Lazarenkova ◽  
Alexander A. Balandin
Keyword(s):  
Quantum Dot ◽  
Phonon Spectrum ◽  
Acoustic Phonon ◽  
Phonon Dispersion ◽  
Three Dimensional ◽  
Semiconductor Quantum Dots ◽  
Low Energy ◽  
Band Formation ◽  
Carrier Relaxation ◽  
Semiconductor Quantum Dot

AbstractWe describe a model for numerical calculation of phonon spectrum in a three-dimensional regimented array of semiconductor quantum dots. Regimentation and possibility of carrier mini-band formation make this structure analogous to a crystal, e.g.quantum dot crystal. It is demonstrated that the acoustic phonon dispersion undergoes strong modification in such a structure leading to emergence of low-energy quasi-optical branches. Strong phonon spectrum modification is expected to affect carrier relaxation and transport properties.

Phase instability and electron-assisted renormalization of acoustic phonon spectrum in free-standing quantum wires

1999 ◽  
Vol 263-264 ◽  
pp. 522-525
Author(s):  
S.M. Komirenko ◽  
K.W. Kim ◽  
V.A. Kochelap ◽  
Mitra Dutta ◽  
Michael A. Stroscio
Keyword(s):  
Phonon Spectrum ◽  
Acoustic Phonon ◽  
Quantum Wires ◽  
Free Standing ◽  
Phase Instability
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