Quantum Confinement Stark Effect of Different Gainnas Quantum Well Structures

2013 ◽  
Vol 773 ◽  
pp. 622-627
Author(s):  
Ying Ning Qiu ◽  
Wei Sheng Lu ◽  
Stephane Calvez
Keyword(s):  
Electric Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
External Electric Field ◽  
Quantum Confinement ◽  
Stark Effect ◽  
Band Gap Energy ◽  
Electron Effective Mass ◽  
Coupled Quantum Wells ◽  
Quantum Well Structures

The quantum confinement Stark effect of three types of GaInNAs quantum wells, namely single square quantum well, stepped quantum wells and coupled quantum wells, is investigated using the band anti-crossing model. The comparison between experimental observation and modeling result validate the modeling process. The effects of the external electric field and localized N states on the quantized energy shifts of these three structures are compared and analyzed. The external electric field applied to the QW not only changes the potential profile but also modulates the localized N states, which causes band gap energy shifts and increase of electron effective mass.

Spontaneous Emission Rate and Radiative Current Density in p-GaAs/i-GaNAsBi/n-GaAs Quantum Well Lasers

2019 ◽  
Vol 16 (11) ◽  
pp. 4474-4478
Author(s):  
Ikram Hassouna Guizani ◽  
Ahmed Alhadi Rebey
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spontaneous Emission ◽  
Current Density ◽  
Stark Effect ◽  
Emission Rate ◽  
Spontaneous Emission Rate ◽  
Doping Density ◽  
Quantum Well Structures ◽  
Quantum Confined Stark Effect

We have theoretically investigated the 1.55 μm emission of p–i–n GaNAsBi-based quantum wells (QWs) using a self-consistent calculation combined with (16×16) BAC model. Their performances are evaluated in terms of spontaneous emission rate Rsp and radiative current density Jrad. We have found that Jrad increases as function of the injected carrier density as well as the doping density. The quantum confined Stark effect on radiative current density in ideal lasers is also discussed. The radiative current density versus well width for simple and double p-GaAs/i-GaN·58yAs1-1·58yBiy/n-GaAs quantum well structures is also examined. We have obtained that Jrad increases with increase average thickness of GaNAsBi active region. The optimization of well parameters can be used as a basis for GaNAsBi-based lasers intended for optical fiber telecommunication wavelength.

Intersubband Transitions in Asymmetric Quantum Wells with External Electric Field

2014 ◽  
Vol 525 ◽  
pp. 170-176
Author(s):  
Zhao Xu Liu ◽  
Jun Zhu ◽  
Si Hua Ha
Keyword(s):  
Electric Field ◽  
Quantum Wells ◽  
External Electric Field ◽  
Electric Fields ◽  
Stark Effect ◽  
Energy Levels ◽  
Intersubband Transitions ◽  
External Electric Fields ◽  
Asymmetric Quantum ◽  
Negative Field

The quantum-confined Stark effect on the optical absorption of intersubband transitions in an asymmetric AlxGa1-xN/In0.3Ga0.7N/GaN quantum wells is investigated by means of the density matrix formulism. The built-in electric field generated by the piezoelectric and spontaneous polarizations competing against to the external electric fields is considered. As the result, the influences of the built-in and external electric fields on the energy potentials and the eigen stares are discussed in detail. When the positive external electric field is applied, the peak values of the absorption coefficients from 3-2, 2-1 and 3-1 transitions are reduced and moved to the lower photon energy levels. With the negative field, the exactly opposite results can be obtained. Moreover, it is indicated that the results of the wavelengths from the 3-2, 2-1 and 3-1 transitions are reduced by the positive external electric field and increased by the negative field.

TWO-PHOTON-ABSORPTION SPECTRA OF QUANTUM-WELL EXCITONS IN STATIC ELECTRIC FIELDS

1991 ◽  
Vol 05 (17) ◽  
pp. 1133-1138
Author(s):  
KAZUHITO FUJII ◽  
AKIRA SHIMIZU ◽  
JOHAN BERGQUIST ◽  
SOTOMITSU IKEDA ◽  
TAKESHI SAWADA
Keyword(s):  
Electric Field ◽  
Quantum Well ◽  
Absorption Spectra ◽  
Electric Fields ◽  
Band Gap Energy ◽  
Photon Absorption ◽  
Static Electric Field ◽  
Quantum Well Structures ◽  
Two Photon Absorption ◽  
Two Photon

We have measured two-photon-absorption spectra of GaAs/Al 0.4 Ga 0.6 As quantum-well structures in a static electric field for photon energies near half the band gap energy, and found drastic field-induced-changes in the spectra. The two-photon-absorption peak at half the energy of the lowest light-hole exciton is induced by the static electric field normal to the quantum well layers, in agreement with a theory that takes account of quasi-two-dimensional exciton effects. With increasing the electric field, however, this peak grows more drastically than the theoretical prediction, and it approaches a large value predicted by another simplified theory based on a two-level model.

Magneto-Optical Studies of GaAs-AlGaAs Modulation Doped Quantum Wells Under Hydrostatic Pressure

1989 ◽  
Vol 160 ◽  
Author(s):  
Weimin Zhou ◽  
Clive H. Perry ◽  
John M. Worlock
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Free Electron ◽  
Pressure Coefficient ◽  
Band Gaps ◽  
Interband Transitions ◽  
Optical Studies ◽  
Electron Effective Mass ◽  
Quantum Well Structures ◽  
First Time

AbstractHigh pressure photoluminescence measurements on modulation doped GaAs-AlGaAs quantum well structures have been performed for the first time with applied magnetic fields up to 15 Tesla. We have observed Landau fans from interband transitions of the 2D free electron gas between 0 and 8.5 kbar. In this pressure range the electron effective mass in GaAs increased at the rate of 2.6% per kbar. Above 9 kbar, the free Landau transitions disappeared and bound magneto-exiton behaviour dominated the spectrum. The influence of pressure on the band-gaps causes a controlled trapping of the free electron from the GaAs well to Si donors (DX centers) in the AlGaAs layers. Above 9 kbar the pressure coefficient of the GaAs band gap was found to be 10.4 meV/kbar which is comparable to the accepted value in undoped GaAs quantum well structures.

The electronic states and the optical absorption for an asymmetrical quantum well applied with an external electric field

2019 ◽  
Vol 33 (26) ◽  
pp. 1950301 ◽  
Author(s):  
Yu Liu ◽  
Youbin Yu
Keyword(s):  
Optical Absorption ◽  
Iterative Method ◽  
Electric Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
External Electric Field ◽  
Electronic States ◽  
Matrix Approach ◽  
Absorption Coefficients ◽  
Asymmetric Quantum

Electric field influences on the electronic states and the optical absorption in an asymmetrical quantum well with semiparabolic potential are investigated. The formula for the absorption coefficients in this asymmetrical quantum well with electric field are deduced by applying iterative method and density-matrix approach. The results are discussed with GaAs/AlGaAs materials and show that the external electric field has a significant effect on the electronic states and absorption coefficients of asymmetric quantum wells.

Cathodoluminescence depth-profiling studies of GaN/AlGaN quantum-well structures

2000 ◽  
Vol 15 (2) ◽  
pp. 495-501 ◽  
Author(s):  
M. Godlewski ◽  
E. M. Goldys ◽  
M. R. Phillips ◽  
R. Langer ◽  
A. Barski
Keyword(s):  
Electric Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
Piezoelectric Effect ◽  
Depth Profiling ◽  
Yellow Emission ◽  
Internal Electric Field ◽  
Edge Emission ◽  
Quantum Well Structures ◽  
Accumulation Of Defects

In this paper we evaluate the in-depth homogeneity of GaN epilayers and the influence of electric field present in strained GaN/AlGaN heterostructures and quantum wells on the yellow and “edge” emission in GaN and AlGaN. Our depth-profiling cathodoluminescence measurements show an increased accumulation of defects at the interface. Inhomogeneities in the doping level are reflected by the enhancement of the yellow emission in the interface region. The piezoelectric effect is found to strongly reduce the emission from the strained AlGaN quantum-well barriers. We also show that Ga droplets, commonly found on surfaces of samples grown in Ga-rich conditions, screen the internal electric field in a structure and thus result in a local enhancement of the edge emission intensity.

Characterization of III-V Semiconductor Structures Using Electron Beam Electroreflectance (EBER) spectroscopy.

1988 ◽  
Vol 144 ◽  
Author(s):  
M. H. Herman ◽  
I. D. Ward ◽  
S. E. Buttrill ◽  
G. L. Francke
Keyword(s):  
Electron Beam ◽  
Quantum Well ◽  
Quantum Wells ◽  
Sample Surface ◽  
Band Gap Energy ◽  
Quantum Well Structures ◽  
Resonant States

ABSTRACTEBER is a form of modulated reflectance spectroscopy in which a low energy electron beam alters the sample surface potential. For III-V semiconductors, the spectra are characteristic of electroreflectance, including excitonic, interband, and impurity transitions. The study of these transitions provides accurate estimations of band gaps in bulk and thick film samples. Measurements of the band gap energy in compounds such as AlxGa1-xAs provide highly precise evaluations of their composition.Additionally, EBER spectra of quantum well structures and heterojunctions provide useful information about the composition and quality of materials and interfaces. For quantum wells, detected features suggest the presence of allowed, disallowed, and resonant states. In EBER spectra of HEMT structures, peaks are apparent resulting from transitions between the valence band and the states in which the electrons are confined. We present examples of EBER determination of AlGaAs composition, single GaAs/AlGaAs quantum well evaluation, and HEMT characterization.

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