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Related papers: Effect of temperature on In_x Ga_(1-x) As/GaAs qua…

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Band edge and energy levels of truncated pyramidal In_x Ga_(1-x) As/GaAs (001) quantum dots are studied by single-band effective mass approach, and the dependence to stoichiometric percentages is investigated. It is shown that enhancement…

Computational Physics · Physics 2015-11-04 Mahdi Ahmadi Borji , Esfandiar Rajaei

In this paper, we have studied the strain, bandedge, and energy levels of cubic InGaAs quantum dots (QDs) surrounded by GaAs. It is shown that overall strain value is larger in InGaAs-GaAs interfaces, and also in smaller QDs. Also, it is…

Computational Physics · Physics 2015-11-04 Esfandiar Rajaei , Mahdi Ahmadi Borji

Quantum dot lasers have been the focus of researchers due to their interesting optical properties owing to quantum confinement of carriers. In epitaxial quantum dots formed on a substrate, band-edge diagrams sound to more complex than…

Computational Physics · Physics 2015-11-04 Esfandiar Rajaei , Mahdi Ahmadi Borji

We report a correlative microscopy study of a sample containing three stacks of InGaN/GaN quantum dots (QDs) grown at different substrate temperature, each stack consisting of 3 layers of QDs. Decreasing the substrate temperature along the…

Materials Science · Physics 2021-06-08 I. Dimkou , J. Houard , N. Rochat , P. Dalapati , E. Di Russo , D. Cooper , A. Grenier , E. Monroy , L. Rigutti

The purpose of this research is to study laser dynamics of InAs/GaAs Quantum Dot Lasers (QDLs) by changing QD energy levels. To date, most of the investigations have focused on only one of these circumstances, and hardly the result of…

Computational Physics · Physics 2015-11-04 Esfandiar Rajaei , Mahdi Ahmadi Borji

We investigate room temperature lasing of terahertz quantum cascade lasers using quantum dot chains as active material suitable for wireless communication and imaging technologies. Bandstructure calculations for such extended systems of…

Mesoscale and Nanoscale Physics · Physics 2021-03-10 Alexander Mittelstädt , Ludwig A. Th. Greif , Stefan T. Jagsch , Andrei Schliwa

We develop a temperature dependent empirical pseudopotential theory to study the electronic and optical properties of self-assembled quantum dots (QDs) at finite temperature. The theory takes the effects of both lattice expansion and…

Materials Science · Physics 2015-06-04 Jianping Wang , Ming Gong , Guang-Can Guo , Lixin He

The temperature of the semiconductor diode increases under strong light illumination whether thermoelectric cooler is installed or not, which changes the output wavelength of the laser (Lee M. S. et al., 2017). However, other…

Quantum Physics · Physics 2018-03-22 Yang-Yang Fei , Xiang-Dong Meng , Ming Gao , Yi Yang , Hong Wang , Zhi Ma

The influence of indium percentage on dynamical characteristics of InxGa1-xAs/GaAs(001) quantum dot lasers (QDLs) is investigated. Energy levels of self-organized truncated-cone-shape QDs are calculated by means of the eight-band k.p model,…

Computational Physics · Physics 2015-11-04 Mahdi Ahmadi Borji , Esfandiar Rajaei

n-type Ge/SiGe terahertz quantum cascade laser are investigated using non-equilibrium Green's functions calculations. We compare the temperature dependence of the terahertz gain properties with an equivalent GaAs/AlGaAs QCL design. In the…

Mesoscale and Nanoscale Physics · Physics 2019-05-01 T. Grange , D. Stark , G. Scalari , J. Faist , L. Persichetti , L. Di Gaspare , M. De Seta , M. Ortolani , D. J. Paul , G. Capellini , S. Birner , M. Virgilio

The correct accounting for thermal effects is always a challenge when one needs to make quantitative predictions for any laser applications. In such complicated devices as quantum cascade lasers temperature strongly affects the operational…

Mesoscale and Nanoscale Physics · Physics 2023-01-20 Ivan I. Vrubel , Evgeniia D. Cherotchenko , Georgii D. Miskovets , Vladislav V. Dudelev , Grigorii S. Sokolovskii

This work studies the effect of temperature on the binding energy of a shallow hydrogenic impurity located on the axis of a cylindrical semiconductor GaAs Al_x Ga_{1-x} As quantum well wire. The results show that the binding energy at a low…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T G Emam

We investigate temperature dependent electronic correlation effects in the conduction bands of Gadolinium Nitride (GdN) based on the combination of many body analysis of the multi-band Kondo lattice model and the first principles TB-LMTO…

Strongly Correlated Electrons · Physics 2010-02-09 A. Sharma , W. Nolting

We discuss the influence of a rapid thermal annealing step on the magneto-optical emission properties of In(Ga)As/GaAs quantum dots. We map out a strong influence of the growth- and anneling parameters on the quantum excitons' effective…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 T. Braun , S. Betzold , N. Lundt , M. Kamp , S. Höfling , C. Schneider

The effect of wetting layers on the strain and electronic structure of InAs self-assembled quantum dots grown on GaAs is investigated with an atomistic valence-force-field model and an empirical tight-binding model. By comparing a dot with…

Materials Science · Physics 2009-11-10 Seungwon Lee , Olga L. Lazarenkova , Fabiano Oyafuso , Paul von Allmen , Gerhard Klimeck

We study (In,Ga)(As,Sb)/GaAs quantum dots embedded in a GaP (100) matrix, which are overgrown by a thin GaSb capping layer with variable thickness. Quantum dot samples are studied by temperature-dependent photoluminescence, and we observe…

Mesoscale and Nanoscale Physics · Physics 2023-09-12 Elisa Maddalena Sala , Petr Klenovský

We investigate the in-plane oscillations of the relaxed shape graphene due to externally applied tensile edge stress along both the armchair and zigzag directions. We show that the total elastic energy density is enhanced with temperature…

Mesoscale and Nanoscale Physics · Physics 2014-11-20 Sanjay Prabhakar , Roderick Melnik , Luis L. Bonilla , Shyam Badu

Temperature dependence of intersubband transitions in AlN/GaN multiple quantum wells grown with molecular beam epitaxy is investigated both by absorption studies at different temperatures and modeling of conduction-band electrons. For the…

This paper discusses the temperature-dependent properties of (GaIn)As/Ga(AsSb)/(GaIn)As W-quantum well heterostructures for laser applications based on theoretical modeling as well as experimental findings. A microscopic theory is applied…

Quantum spin Hall insulators (QSHIs) based on HgTe and three-layer InAs/GaSb quantum wells (QWs) have comparable bulk band-gaps of about 10--18~meV. The former however features a band-gap vanishing with temperature, while the gap in…

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