Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "quantum well" wg kryterium: Temat


Tytuł:
Design and analytical calculations of the width and arrangement of quantum well and barrier layers in GaN/AlGaN LED to enhance the performance
Autorzy:
Sharma, L.
Sharma, R.
Tematy:
barrier
multi quantum well
light emitting diode
power efficiency
quantum well
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:
https://bibliotekanauki.pl/articles/2063882.pdf  Link otwiera się w nowym oknie
Opis:
This research paper discusses an analytical approach to designing the active region of light emitting diodes to enhance its performance. The layers in the active region were modified and the effects of changing the width of quantum well and barrier layers in a multi-quantum light emitting diode on the output power and efficiency have been investigated. Also, the ratio of the quantum well width to the B layer width was calculated and proposed in this research paper. The study is carried out on two different LED structures. In the first case (i.e., first structure), the width of the quantum well layers is kept constant while the width of the B layers is varied. In the second case (i.e., second structure), both the quantum well and B layer widths are varied. Based on the simulation results, it has been observed that the LED power efficiency increases considerably for a given quantum well to B layers width ratio without increasing the production complexity. It is also seen that for a desired power efficiency the width of quantum well should be between 0.003 μm and 0.006 μm, and the range of B width (height) should be 2.2 to 6 times the quantum well width. The proposed study is carried out on the GaN-AlGaN-based multi-quantum well LED structure, but this study can be extended to multiple combinations of the semiconductor structures.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oscillator strength of optical transitions in InGaAsN/GaAsN/GaAs quantum wells
Autorzy:
Mika, A
Sek, G
Ryczko, K
Kozub, M
Musial, A
Marynski, A
Misiewicz, J
Langer, F
Höfling, S
Appel, T
Kamp, M
Forchel, A
Tematy:
dilute nitride
quantum well
oscillator strength
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/173586.pdf  Link otwiera się w nowym oknie
Opis:
Experimental and theoretical considerations and results on the effect of nitrogen incorporation on the oscillator strength of optical transitions in InGaNAs/GaAs quantum wells (QWs) are presented. Therefore, a set of dilute nitride quantum well structures was grown by molecular beam epitaxy. Optical investigation via spectroscopic methods have been performed at various temperatures for both the as-grown samples, and after rapid thermal annealing. The fundamental transition energy and its oscillator strength vs. the QW composition have been systematically investigated. Additionally, the effect of the bandgap discontinuities on the transitions intensity has also been considered. The experimental data have been confronted with the band structure calculations within the effective mass approximation employing a two level repulsion model for the nitrogen-containing structures. The obtained results are crucial for possible future applications employing the quantum well in cavity structures and bringing the practical exploitation of quantum electrodynamics phenomena to the telecommunication spectral range.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grating-free high-x InP/InxGa1-xAs mid-wavelength infrared QWIP focal plane array
Autorzy:
Besikci, Cengiz
Balcı, Saadettin V.
Tanış, Onur
Güngör, Oğuz O.
Arpaguş, Esra S.
Tematy:
infrared imaging
quantum well
infrared photodetector
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:
https://bibliotekanauki.pl/articles/2204209.pdf  Link otwiera się w nowym oknie
Opis:
The authors report the characteristics of a diffraction-grating-free mid-wavelength infrared InP/In₀.₈₅Ga₀.₁₅As quantum well infrared photodetector focal plane array with a 640 × 512 format and a 15 µm pitch. Combination of a normal incident radiation sensing ability of the high-x InxGa1-xAs quantum wells with a large gain property of the InP barriers led to a diffraction-grating-free quantum well infrared photodetector focal plane array with characteristics displaying great promise to keep the status of the quantum well infrared photodetector as a robust member of the new generation thermal imaging sensor family. The focal plane array exhibited excellent uniformity with noise equivalent temperature difference nonuniformity as low as 10% and a mean noise equivalent temperature difference below 20 mK with f/2 optics at 78 K in the absence of grating. Elimination of the diffraction-grating and large enough conversion efficiency (as high as ~70% at a -3.5 V bias voltage) abolish the bottlenecks of the quantum well infrared photodetector technology for the new generation very small-pitch focal plane arrays.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Overhauser effect and anisotropy of electron spin g-factor in GaAs / AlGaAs quantum wells
Autorzy:
Ito, T.
Shichi, W.
Ichida, M.
Gotoh, H.
Kamada, H.
Ando, H.
Tematy:
quantum well
electron spin g-factor
Overhouser effect
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Powiązania:
https://bibliotekanauki.pl/articles/385175.pdf  Link otwiera się w nowym oknie
Opis:
To investigate the dependence of electron g-factor on magnetic field in GaAs / AlGaAs quantum wells time-resolved photoluminescence measurements under a high magnetic field in different experimental configuration, the magnetic field perpendicular (g up tack ) and parallel (g II) to the quantum confinement direction, has been studied. When the angle between the magnetic field and the confinement direction is 45°, the precession frequency varies depending on polarity of magnetic field and the circular polarization type of excitation light (sigma+ or sigma-). We found that these dependences of the precession frequency exhibit main features of Overhauser effect with an effective magnetic field of 0.5 T that nuclear spins react back on electron spin precession and the g-factor value is not affected by the effective magnetic field. The g+ and gii values agree well with the results of four-band k • p perturbation calculations.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emission-intensity-enhanced GaN-based LED based on multilayer grating structures
Autorzy:
Li, Xin
Sun, Dejie
Han, Kun
Cao, Lijun
Guo, Shiliang
Li, Zhiquan
Tematy:
light-emitting diode
surface plasmon
grating
quantum well
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/2033893.pdf  Link otwiera się w nowym oknie
Opis:
A novel surface-plasmon-enhanced GaN-LED is proposed to improve the emission efficiency of the traditional LED. The SiO2 film, Ag triangular structure and ITO film were coated on the rectangularly-patterned p-GaN layer sequentially, which can form the quasi-symmetrical waveguide structure to enhance the internal quantum efficiency and the light extraction efficiency. The COMSOL software is used to simulate the LED structure. The radiated powers, absorbed powers and distribution of electric field are obtained and analyzed. The results reveal that emission efficiency of the proposed GaN-LED can be greatly improved.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peculiarities in optical response of hybrid-barrier GaSb/InAs/AlSb resonant tunneling diode structure
Autorzy:
Dyksik, M.
Motyka, M.
Rygała, M.
Pfenning, A.
Hartmann, F.
Weih, R.
Worschech, L.
Höfling, S.
Sęk, G.
Tematy:
resonant tunneling diode
quantum well
optical spectroscopy
photoluminescence
photoreflectance
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/1835778.pdf  Link otwiera się w nowym oknie
Opis:
We present comprehensive investigation of the optical properties of hybrid-barrier GaSb-based resonant tunneling structures, containing a bulk-like GaInAsSb absorption layer and two asymmetric type II GaSb/InAs/AlSb quantum wells. Methods of optical spectroscopy by means of Fourier-transformed photoluminescence and photoreflectance are employed to probe optical transitions in this complex multilayer system. Based on the comparison between the absorption-like and emission-like spectra (also in function of temperature) confronted with band structure calculations four main transitions could be resolved and identified. For one of them, there has been observed unusually strong linear polarization dependence never reported in structures of that kind. It has been interpreted as related to a transition at the GaSb/GaInAsSb interface, for which various scenarios causing the polarization selectivity are discussed.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical MIDO : Multiple Inputs-Digital Output : device
Autorzy:
Alaiz-Gudin, Antonio M.
González-Marcos, Ana P.
Tematy:
distributed feedback laser
multi quantum well
optical bistability
semiconductor laser
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:
https://bibliotekanauki.pl/articles/2063884.pdf  Link otwiera się w nowym oknie
Opis:
Advances in photonic technologies, with new processes and scopes of photonic integrated circuits, have generated a lot of interest as the field allows to obtain sensors with reduced size and cost and build systems with high interconnectivity and information density. In this work, answering the needs of photonic sensors that must be portable, more energy- efficient, and more accurate than their electrical counterparts, also with a view to the emerging field of neuromorphic photonics, a versatile device is presented. The proposed device makes use of the well-known advantages provided by optical bistability. By combining two distributed feedback-multi quantum well semiconductor laser structures, this new optical multiple inputs - digital output device offers various essential purposes (such as logic gates, wavelength detector and monitoring) with no need for specific manufacturing for each of them. Through a commercial computer-aided design tool, VPIphotonics™, the necessary characterization of proposed device is also described.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of Exciton-Polaritons
Autorzy:
De Silva, L. M. S.
Wijewardena Gamalath, K. A. I. L.
Tematy:
AlGaAs/AlAs
CdSe/ZnS
Exciton-polaritons
GaAs
distributed Bragg reflectors
microcavity
quantum well
Pokaż więcej
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:
https://bibliotekanauki.pl/articles/1166216.pdf  Link otwiera się w nowym oknie
Opis:
To study the generation of exciton polaritons in a quantum well embedded in a semiconductor Fabry-Pérot microcavity with distributed Brag reflectors, a simple semi-classical auxiliary differential equation based model is proposed. The solutions are obtained using FDTD method considering only the excitations from ground to next excited states and one single QW resonance. The simulations are presented for GaAs quantum well in Al0.1Ga0.9As microcavity and a ZnS quantum well embedded in CdSe microcavity with 12 DBR layers on either side. Model is proved to be stable and agrees with properties of polarization associated with polariton dispersion. Results show that GaAs is a better quantum well material to generate polaritons than CdSe.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of quantum-well states and carrier scattering times in discontinuities of opto-electrical characteristics of SCH lasers
Autorzy:
Kozioł, Z
Matukhin, S I
Buduleva, E A
Tematy:
SCH laser
quantum well
heterostructure
carrier scattering time
AlGaAs
discontinuous
I-V characteristics
Pokaż więcej
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/175012.pdf  Link otwiera się w nowym oknie
Opis:
Drift-diffusion computer simulation model available in Synopsys’ Sentaurus TCAD User Guide is used to study electrical and optical characteristics of a separate-confinement heterostructure laser based on AlGaAs. We investigate the role of the width and depth of quantum-well active region, below and above the lasing threshold. The device properties depend on both, the number of bound quantum-well states and on closeness of the highest bound states to conduction or valence band offset. The lasing action may not exist at certain widths or depths of quantum-well, and the threshold current is a discontinuous function of these parameters, at such values of quantum-well width or depth when the highest quantum-well bound states cross conduction or valence band energy offset. The effects are more pronounced at low temperatures. Discontinuities in characteristics are found, at certain conditions, in temperature dependences as well. The carriers scattering time on quantum-well is shown to have a crucial role for the amplitude of discontinuities of these characteristics. The current below the lasing threshold and the threshold current density itself decrease with an increase of quantum-well scattering times and the amplitude of discontinuities decreases then as well.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Materiały Elektroniczne 2005 T.33 nr 1/4
Badanie profilu składu chemicznego i lateralnej jednorodności studni kwantowych związków półprzewodnikowych AIIIBV = The investigation of the chemical composition profile and laterial homogenity of AIIIBV quatum wells
Badanie profilu składu chemicznego i lateralnej jednorodności studni kwantowych związków półprzewodnikowych AIIIBV
Autorzy:
Gaca Jarosław
Wydawca:
ITME
Powiązania:
Materiały Elektroniczne
Electronic Materials
Opis:
5-42 s. : il. 24 cm.
Bibliogr. s. 41-42
Dostawca treści:
RCIN - Repozytorium Cyfrowe Instytutów Naukowych
Książka

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies