scholarly journals Quantum-well thickness dependence of spin polarization of excitons

2011 ◽  
Vol 1 (1) ◽  
pp. 5
Author(s):  
M. Idrish Miah
Keyword(s):  
Phase Space ◽  
Electric Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
Spin Polarization ◽  
Optical Orientation ◽  
Space Filling ◽  
Circularly Polarized ◽  
Semiconductor Quantum Wells ◽  
Left And Right

The optical orientation of exciton spins in semiconductor quantum wells (SQWs) was investigated by observing the circular polarization of the photoluminescence (PL). The left/right circularly polarized PL in SQWs was measured. It was found that there is a difference between the two different polarization conditions, which is caused by spin-dependent phase-space filling. The PL polarization was estimated from the signals of the left and right circularly polarized PL and was found to depend on the well thickness of SQWs as well as on the sample temperature. The influence of an electric field on the PL polarization was studied.

INFLUENCE OF NONLINEAR ELECTRON MOBILITY ON RESPONSE TIME IN PHOTOREFRACTIVE SEMICONDUCTOR QUANTUM WELLS

2012 ◽  
Vol 21 (04) ◽  
pp. 1250050 ◽  
Author(s):  
MAREK WICHTOWSKI ◽  
ANDRZEJ ZIOLKOWSKI ◽  
EWA WEINERT-RACZKA ◽  
BLAZEJ JABLONSKI ◽  
WOJCIECH KARWECKI
Keyword(s):  
Electric Field ◽  
Quantum Wells ◽  
Electron Mobility ◽  
Hot Electrons ◽  
Nonlinear Transport ◽  
Field Range ◽  
Fringe Contrast ◽  
Recording Time ◽  
Semiconductor Quantum Wells ◽  
Charge Field

Nonlinear transport of hot electrons in semi-insulating GaAs / AlGaAs quantum wells significantly affects their photorefractive properties. In case of two waves mixing, this influence consists, among others, in an increased shift of photorefractive grating relative to light intensity distribution. The influence of nonlinear transport on grating recording time is less examined experimentally and theoretically. This study compares numerical and analytical solutions describing grating dynamics in approximation of small fringe contrast. The influence of nonlinear electron mobility on space-charge field was examined depending on external electric field intensity and on the grating constant. It was found that in the electric field range below 20 kV/cm, the nonlinear transport of electrons does not shorten the grating generation time.

scholarly journals Current-Induced Spin Photocurrent in GaAs at Room Temperature

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 399
Author(s):  
Yang Zhang ◽  
Yu Liu ◽  
Xiao-Lan Xue ◽  
Xiao-Lin Zeng ◽  
Jing Wu ◽  
...  
Keyword(s):  
Electric Field ◽  
Spin Polarization ◽  
Applied Electric Field ◽  
Room Temperature ◽  
Polarization Direction ◽  
Applied Bias ◽  
Applied Bias Voltage ◽  
Sample Plane ◽  
Bulk Gaas ◽  
Circularly Polarized

Circularly polarized photocurrent, observed in p-doped bulk GaAs, varies nonlinearly with the applied bias voltage at room temperature. It has been explored that this phenomenon arises from the current-induced spin polarization in GaAs. In addition, we found that the current-induced spin polarization direction of p-doped bulk GaAs grown in the (001) direction lies in the sample plane and is perpendicular to the applied electric field, which is the same as that in GaAs quantum well. This research indicates that circularly polarized photocurrent is a new optical approach to investigate the current-induced spin polarization at room temperature.

scholarly journals Внутризонное поглощение излучения дырками в квантовых ямах InAsSb/AlSb и InGaAsP/InP

2018 ◽  
Vol 52 (2) ◽  
pp. 207
Author(s):  
Н.В. Павлов ◽  
Г.Г. Зегря ◽  
А.Г. Зегря ◽  
В.Е. Бугров
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Incident Radiation ◽  
Radiation Absorption ◽  
Hole Density ◽  
Internal Radiation ◽  
Radiation Losses ◽  
Semiconductor Quantum Wells ◽  
Quantum Well Width ◽  
Split Band

AbstractMicroscopic analysis of intraband radiation absorption by holes with their transition to the spin-split band for InAsSb/AlSb and InGaAsP/InP semiconductor quantum wells is performed in the context of the four-band Kane model. The calculation is performed for two incident-radiation polarizations: along the crystal-growth axis and in the quantum-well plane. It is demonstrated that absorption with transition to the discrete spectrum of spin-split holes has a higher intensity than absorption with transitions to the continuous spectrum. The dependences of the intraband absorption coefficient on temperature, hole density, and quantum- well width are thoroughly analyzed. It is shown that intraband radiation absorption can be the main mechanism of internal radiation losses in lasers based on quantum wells.

Strain-Induced Lateral Confinement of Carriers in Semiconductor Quantum Wells

1988 ◽  
Vol 144 ◽  
Author(s):  
K. Kash ◽  
R. Bhat ◽  
Derek D. Mahoney ◽  
J.M. Worlock ◽  
P.S.D. Lin ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Band Gap ◽  
Red Shift ◽  
Lateral Confinement ◽  
Semiconductor Quantum Wells ◽  
20 Nm ◽  
Ingaas Quantum Well

ABSTRACTWe describe here an effort to provide lateral confinement of carriers within a continuous InGaAs quantum well by creating a pattern of strain in the well. A compressed InGaAsP layer overlying the quantum well and the InP barrier was patterned into submicron stressor wires by etching to within approximately 20 nm of the InP barrier. The relaxation of the compression at the edges of the quaternary stressors resulted in dilation of the quantum well material under their centers, thus lowering the band gap of the material, providing confinement for both electrons and holes there. We observed a red shift of the quantum well luminescence of 7 meV for 400 nm wide wires, evidence for the strain-induced lateral confinement. This is the first observation of a red-shifted band gap in submicron strain-confining structures.

Electron-spin polarization near the Fermi level inn-type modulation-doped semiconductor quantum wells

1999 ◽  
Vol 59 (12) ◽  
pp. R7813-R7816 ◽  
Author(s):  
A. L. C. Triques ◽  
J. Urdanívia ◽  
F. Iikawa ◽  
M. Z. Maialle ◽  
J. A. Brum ◽  
...  
Keyword(s):  
Fermi Level ◽  
Quantum Wells ◽  
Spin Polarization ◽  
Electron Spin ◽  
Electron Spin Polarization ◽  
Semiconductor Quantum Wells
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