Quantum Well Research Papers - Academia.edu (original) (raw)

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- Engineering, Applied Physics, Organic Semiconductor Laser, Physical sciences
- by Titus Sandu and +1
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- Quantum Optics, Luminescence, Optical physics, Coherent States
- by John Bowers
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- Engineering, Applied Physics, Photoluminescence, Quantum Dots
- by Navin Patel
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- Semiconductor Devices, Band Structure, Band Gap, Current Density
- by S. Koshiba
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- Crystal Growth, Photoluminescence, Molecular beam epitaxy, Optical Waveguide
- by Joel Eymery
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- Quantum Confinement, Physical sciences, Quantum Efficiency, Optical Properties
- by Michael Santos
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- Proceedings, Sensors, Radiation Detectors, Photodetectors
- by Edward Whittaker
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- Engineering, Quantum Cascade Lasers, Applied Physics, High Frequency

The dynamic characteristics of an edge-emitting laser under large-signal modulation are analyzed in the frequency domain using a harmonic balance method on device level. The simulations reveal the nonlinearities of the carrier dynamics in... more

- by Dalma Novak
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- Quantum Physics, Time-Delay Systems, Damping, Predictive models
- by Michele Ortolani
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- Physical sciences, Terahertz, Electronic Structure, CHEMICAL SCIENCES
- by Vincenzo Lordi
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- Band Gap, Current Density, Optical physics, Quantum Dot
- by Utpal Das
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- Materials Science, Semiconductor Devices, Molecular beam epitaxy, Optoelectronics
- by G. Fasching
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- Organic Semiconductor Laser, Terahertz, Quantum Well, Growth rate
- by Scott Messenger
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- Biomedical Engineering, RADIATION DAMAGE, Gallium nitride, Nuclear science
- by NIKHIL SHARMA
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- Crystal Growth, Transmission Electron Microscopy, Dislocations, High Resolution
- by Stefan Kettemann
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- Materials Engineering, Solar Cell, Nanotechnology, Temperature Gradient
- by G. Erbert and +2
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- Epitaxial Growth, Solid State Laser, Organic Semiconductor Laser, Passive Cooling

We report the demonstration of a N-polar InGaN based green light emitting diode (LED) grown by N2 plasma-assisted molecular beam epitaxy (PAMBE). High quality multiple quantum well LEDs with In0.29Ga0.71N quantum wells were grown at a temperature of 600 °C by applying a new growth model. LED structures exhibited green emission, and electroluminescence measurements on the test structure showed peak emission wavelengths varying from 564.5 to 540 nm. The full width at half-maximum reduced from 74 to 63 nm as the drive current was increased to 180 A/cm2. This work is the first demonstration of an N-polar LED with emission in the green wavelength range.

- by Digbijoy Nath
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- Molecular beam epitaxy, Mathematical Sciences, Physical sciences, Quantum Well

We report highly efficient red phosphorescent organic light-emitting diodes with a triplet p-i-n single quantum well (QW) structure. This p-i-n single QW structure is realized using p-doped and n-doped wide band-gap hole and electron injection and transporting layers with narrow band-gap host and dopant materials. The maximum current and power efficiencies of 11.1 cd/A and 14.4 lm/W, respectively, are demonstrated by a good carrier confinement effect of QW. Very low driving voltage characteristics of 3.7 ∼ 3.9 V at 1000 cd/m2 are realized by almost no injection barrier with high conductivity configuration in our p-i-n structure.

- by Jung Soo Park
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- Engineering, Liquid Crystals, Organic Electronics, Organic light emitting diodes

GaAs/GaAlAs/GaAs Asymmetric Quantum Wells (AQW) have shown in the past multiple advantages in the domain of inter-sub-band transition (ISBT) while serving as the basic structures for advanced electro-optical devices. A new approach enables to create and control the modulation of Self-Induced Electrical Fields (SIEF), as a function of the dopant concentration variation in the structure. Combined numerical and analytical analyses present a smart way to design such structures towards their future integration in advanced devices. The results are obtained by means of Comsol software which needed solid and creative adaptations in order to deal with this kind of challenging structure.

- by Avi Karsenty and +1
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- Modeling and Simulation, Asymmetry, Comsol Multiphysics Simulation, Quantum Well
- by Pierre Lefebvre
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- Materials Engineering, Condensed Matter Physics, Nanotechnology, Quantum Well
- by A. Fissel
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- Multidisciplinary, Molecular beam epitaxy, Silicon Carbide, Quantum Well
- by Bernt Ketterer and +2
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- Resonance Raman Spectroscopy, Transmission Electron Microscopy, Nanowires, Solid State electronic devices

In our research group, we develop novel dots-in-a-well (DWELL) photodetectors that are a hybrid of the quantum dot infrared photodetector (QDIP). The DWELL detector consists of an active region composed of InAs quantum dots embedded in InGaAs quantum wells. By adjusting the InGaAs well thickness, our structure allows for the manipulation of the operating wavelength and the nature of the

- by David Ramirez
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- Molecular beam epitaxy, New Mexico, Infrared, Quantum Dot
- by Gerald Bastard
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- Quantum Well, Relaxation Time
- by Steven Denbaars
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- Engineering, Quantum Confinement, Physical sciences, Optical Properties

The inability of a single-gap solar cell to absorb energies less than the band-gap energy is one of the intrinsic loss mechanisms which limit the conversion efficiency in photovoltaic devices. New approaches to “ultra-high” efficiency solar cells include devices such as multiple quantum wells (QW) and superlattices (SL) systems in the intrinsic region of a p-i-n cell of wider band-gap energy (barrier or host) semiconductor. These configurations are intended to extend the absorption band beyond the single gap host cell semiconductor. A theoretical model has been developed to study the performance of the strain-balanced GaAsP/InGaAs/GaAs MQWSC, and GaAs/GaInNAs MQWSC or SLSC. Our re-sults show that conversion efficiencies can be reached which have never been obtained before for a single-junction solar cell.

- by Maykel Courel Piedrahita
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- Modeling, Solar Cell, Solar Energy, Quantum Well
- by A. Jasik and +1
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- Materials Engineering, Arsenic, Solid State Laser, Molecular beam epitaxy

Abstract: A theoretical investigation of the trion formation process from free carriers in a single GaAs/Al_ {1-x} Ga_ {x} As quantum well is presented. The mechanism for the formation process is provided by the interaction of the electrons and holes with phonons. The contributions from both the acoustic and optical phonons are considered. The dependence of both bi-molecular and tri-molecular formation rates on temperature is calculated. We demonstrate that they are equivalent for negatively and positively charged ...

- by Benoit Deveaud
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- Materials Science, Quantum Well
- by Miguel Ferrada Gutiérrez
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- Carbon Nanotubes, Nanomaterials, Nanoparticles, Nanotechnology
- by David Miller
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- Quantum Physics, Integrated Optics, Optical physics, Effective mass
- by Boon Ooi
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- Quantum Physics, Heat Treatment, Organic Semiconductor Laser, Temperature Dependence
- by John Bowers
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- Quantum Physics, Numerical Analysis, Density dependence, Quantum Efficiency
- by Dr.Anirban Bhattacharyya
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- Engineering, Physics, III-V Semiconductors, Applied Physics
- by Frank Bugge
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- Quantum Physics, Organic Semiconductor Laser, Optical physics, High Power

The optical output power of a laser diode can be enhanced by anti-reflection (AR) and high-reflection (HR) facet coatings, respectively, at the front and back facet. AR and HR coatings also serve the purpose of protection and passivation of laser diode facets. In this work, we have designed and optimized a single layer λ/4 thick Al2O3 film for the AR coating and a stack of λ/4 thick Al2O3/λ/4 thick Si bi-layers for the HR coating for highly strained InGaAs quantum-well edge emitting broad area (BA) laser diodes. Effect of the front and back facet reflectivities on output power of the laser diodes has been studied. The light output versus injected current (L–I characteristics) measurements were carried out on selected devices before and after the facet coatings. We have also carried out the numerical simulation and analysis of L–I characteristics for this particular diode structure. The experimental results have been compared and verified with the numerical simulation.

- by Vipul Kheraj
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- Numerical Simulation, Thin Film, Optical physics, Quantum Well

Chirally stacked N-layer graphene systems with N >= 2 exhibit a variety of distinct broken symmetry states in which charge density contributions from different spins and valleys are spontaneously transferred between layers. We explain how these states are distinguished by their charge, spin, and valley Hall conductivities, by their orbital magnetizations, and by their edge state properties. We argue that valley Hall states have [N/2] edge channels per spin-valley.

- by Jeil Jung
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- Solid State electronic devices, Physical sciences, Quantum Hall Effect, Quantum Well
- by figen boz
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- Materials Engineering, Physics, Condensed Matter Physics, Materials Science
- by Michael Shur
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- Engineering, III-V Semiconductors, Applied Physics, Solid State electronic devices
- by Pierluigi Debernardi
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- Band Structure, Excitons, Variational Methods, Quantum Wells

AlxGayIn1−x−yAs/InP strained-layer multiple-quantum-well lasers emitting at 1.3 µm have been grown by solid source molecular beam epitaxy, and the performance characteristics have been studied. The lasers contain 4, 5, or 6 compressively strained quantum wells in the active region. They exhibit low transparency current densities, high gain coefficients, and high characteristic temperatures compared to conventional GaInAsP/InP quantum well lasers. The results show that desired lasing features can be achieved with relatively simple layer structures if the doping profiles and waveguide structures are properly designed and the material is grown to high structural perfection.

For a long time, one of my dreams was to describe the nature of uncertainty axiomatically, and it looks like I've finally done it in my co∼eventum mechanics! Now it remains for me to explain to everyone the co∼eventum mechanics in the most approachable way. This is what I'm trying to do in this work. The co∼eventum mechanics is another name for the co∼event theory, i.e., for the theory of experience and chance which I axiomatized in 2016 [1, 2]. In my opinion, this name best reflects the co∼event-based idea of the new dual theory of uncertainty, which combines the probability theory as a theory of chance, with its dual half, the believability theory as a theory of experience. In addition, I like this new name indicates a direct connection between the co∼event theory and quantum mechanics, which is intended for the physical explanation and description of the conict between quantum observers and quantum observations [4]. Since my theory of uncertainty satises the Kolmogorov axioms of probability theory, to explain this co∼eventum mechanics I will use a way analogous to the already tested one, which explains the theory of probability as a theory of chance describing the results of a random experiment. The simplest example of a random experiment in probability theory is the " tossing a coin ". Therefore, I decided to use this the simplest random experiment itself, as well as the two its analogies: the " "flipping a coin " and the " spinning a coin " to explain the co∼eventum mechanics, which describes the results of a combined experienced random experiment. I would like to resort to the usual for the probability theory " coin-based " analogy to explain (and first of all for myself) the logic of the co∼eventum mechanics as a logic of experience and chance. Of course, this analogy one may seem strange if not crazy. But I did not come up with a better way of tying the explanations of the logic of the co∼eventum mechanics to the coin-based explanations that are commonly used in probability theory to explain at least for myself the logic of the chance through a simple visual " coin-based " model that clarifies what occurs as a result of a combined experienced random experiment in which the experience of observer faces the chance of observation. I hope this analogy can be useful not only for me in understanding the co∼eventum mechanics.

- by C. Kisielowski
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- Materials Engineering, Condensed Matter Physics, Materials Science, Chemistry
- by figen boz
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- Materials Engineering, Condensed Matter Physics, Materials Science, Nanotechnology
- by John Bowers
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- Dispersion, Band Structure, Semiconductor Lasers, Quantum Wells
- by William Frensley
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- Binding Energy, Quantum Well, Bound States, Resonant Tunneling
- by Paulo Morais
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- Engineering, Chemical Physics, Band Structure, Physical sciences

We provide a broad review of fundamental electronic properties of two-dimensional graphene with the emphasis on density and temperature dependent carrier transport in doped or gated graphene structures. A salient feature of our review is a critical comparison between carrier transport in graphene and in two-dimensional semiconductor systems (e.g. heterostructures, quantum wells, inversion layers) so that the unique features of graphene electronic properties arising from its gap- less, massless, chiral Dirac spectrum are highlighted. Experiment and theory as well as quantum and semi-classical transport are discussed in a synergistic manner in order to provide a unified and comprehensive perspective. Although the emphasis of the review is on those aspects of graphene transport where reasonable consensus exists in the literature, open questions are discussed as well. Various physical mechanisms controlling transport are described in depth including long- range charged impurity scattering, screening, short-range defect scattering, phonon scattering, many-body effects, Klein tunneling, minimum conductivity at the Dirac point, electron-hole puddle formation, p-n junctions, localization, percolation, quantum-classical crossover, midgap states, quantum Hall effects, and other phenomena.

- by Enrico Rossi
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- Physical sciences, Long Range, Electron Transport, Electronic properties