Anomalous Temperature dependence of Fermi-edge Singularity in Modulation-doped AlGaAs/InGaAs/GaAs hetero-structures

2005 ◽  
Vol 872 ◽  
Author(s):  
K. Gopalakrishna Naik ◽  
K.S.R.K. Rao ◽  
T. Srinivasan ◽  
R. Muralidharan ◽  
S. K. Mehta
Keyword(s):  
Excitation Power ◽  
Anomalous Behavior ◽  
Electron Hole ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity ◽  
Pl Intensity ◽  
Dimensional Electron Gas ◽  
Increasing Temperature ◽  
Hole Recombination

AbstractThe temperature and power dependence of Fermi-edge singularity (FES) in high-density two-dimensional electron gas, specific to pseudomorphic AlxGa1-xAs/InyGa1-yAs/GaAs heterostructures is studied by photoluminescence (PL). In all these structures, there are two prominent transitions E11and E21considered to be the result of electron-hole recombination from first and second electron sub-bands with that of first heavy-hole sub-band. FES is observed approximately 5 -10 meV below the E21transition. At 4.2 K, FES appears as a lower energy shoulder to the E21transition. The PL intensity of all the three transitions E11, FES and E21grows linearly with excitation power. However, we observe anomalous behavior of FES with temperature. While PL intensity of E11and E21decrease with increasing temperature, FES transition becomes stronger initially and then quenches-off slowly (till 40K). Though it appears as a distinct peak at about 20 K, its maximum is around 7 - 13 K.

Excitonic enhancement of the Fermi-edge singularity in a dense two-dimensional electron gas

1992 ◽  
Vol 45 (15) ◽  
pp. 8464-8477 ◽  
Author(s):  
W. Chen ◽  
M. Fritze ◽  
W. Walecki ◽  
A. V. Nurmikko ◽  
D. Ackley ◽  
...  
Keyword(s):  
Electron Gas ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity ◽  
Dimensional Electron Gas

ANDERSON-FANO TRANSITIONS IN PHOTOLUMINESCENCE OF A TWO DIMENSIONAL ELECTRON GAS

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1429-1434 ◽  
Author(s):  
L. BRYJA ◽  
A. WÓJS ◽  
K. RYCZKO ◽  
K. WÓJCIK ◽  
J. MISIEWICZ ◽  
...  
Keyword(s):  
Electron Gas ◽  
Photoluminescence Spectra ◽  
Dimensional Electron ◽  
Many Body ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity ◽  
Dimensional Electron Gas ◽  
The Many ◽  
The Magnetic Field

The many body interaction are investigated in polarization resolved photoluminescence in the magnetic field up to 23 T. The Fermi edge singularity, Anderson-Fano transition and neutral and negatively charged excitons (trions) are detected in the photoluminescence spectra. The experimental results are supplemented by realistic calculations.

RENORMALIZATION OF POTENTIAL SCATTERING IN A ONE-DIMENSIONAL NON-LUTTINGER LIQUID: CONDUCTION AND X-RAY FERMI-EDGE SINGULARITY

1995 ◽  
Vol 09 (05) ◽  
pp. 249-269
Author(s):  
DONGXIAO YUE
Keyword(s):  
Luttinger Liquid ◽  
Scattered Wave ◽  
Zeeman Splitting ◽  
Electron System ◽  
Potential Scattering ◽  
Differential Conductance ◽  
One Dimensional ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity

We review some of our recent results on the potential scattering in a weakly interacting one-dimensional(1D) electron gas. The technique we developed is a poor man's renormalization group procedure in the scattered wave basis. This technique can treat the renormalizations of the scattering on the barrier and the scattering between the electrons in a coherent way, and it allows us to find the scattering amplitudes on a localized potential of arbitrary strength for electrons at any energy. The obtained phase shifts are used to study the Fermi-edge singularity in an interacting 1D electron system, where anomalous exponent of the power-law singularity in the vicinity of the edge is found. The transmission coefficient is directly related to the conductance of a 1D channel by the Landauer formula. Simple formulas that describe the conductance at any temperature are derived. In spin-[Formula: see text] systems, the electron–electron backscattering induces renormalizations of the interaction constants, which causes the low-temperature conductance to deviate from the results of the Luttinger liquid theory. In particular, the temperature dependence of the conductance may become nonmonotonic. In the presence of a magnetic field, backscattering gives rise to a peak in the differential conductance at bias equal to the Zeeman splitting.

Fermi-edge singularity in heavily doped GaAs multiple quantum wells

1989 ◽  
Vol 40 (17) ◽  
pp. 12017-12019 ◽  
Author(s):  
H. Kalt ◽  
K. Leo ◽  
R. Cingolani ◽  
K. Ploog
Keyword(s):  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity ◽  
Heavily Doped

Fermi-edge singularity in the luminescence spectra of II-VI modulation-doping quantum wells

1997 ◽  
Vol 55 (12) ◽  
pp. R7391-R7393 ◽  
Author(s):  
G. Coli' ◽  
L. Calcagnile ◽  
P. V. Giugno ◽  
R. Cingolani ◽  
R. Rinaldi ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Luminescence Spectra ◽  
Modulation Doping ◽  
Edge Singularity ◽  
Fermi Edge ◽  
Fermi Edge Singularity

scholarly journals Photocatalytic Liquid-Phase Selective Hydrogenation of 3-Nitrostyrene to 3-vinylaniline of Various Treated-TiO2 Without Use of Reducing Gas

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 329 ◽  
Author(s):  
Okorn Mekasuwandumrong ◽  
Saknarin Chaitaworn ◽  
Joongjai Panpranot ◽  
Piyasan Praserthdam
Keyword(s):  
Selective Hydrogenation ◽  
Consumption Rate ◽  
Rutile Phase ◽  
Optimum Amount ◽  
Electron Hole ◽  
Tio2 Photocatalysts ◽  
Reducing Gas ◽  
Pl Intensity ◽  
Different Gases ◽  
Hole Recombination

In this work, we investigate the effect of TiO2 properties on the photocatalytic selective hydrogenation of 3-nitrostyrene (3-NS) to 3-vinylaniline (3-VA). The P25-TiO2 photocatalysts were calcined at 600–900 °C using different gases (Air, N2, and H2) and characterized by XRD, N2 physisorption, XPS, UV-Vis, and PL spectroscopy. In the photocatalytic hydrogenation of 3-nitrostyrene in isopropanol, the selectivity of 3-vinylaniline of the treated TiO2 was almost 100%. A linear correlation between the 3-NS consumption rate and PL intensity was observed. Among the catalysts studied, P25-700-air, which possessed the lowest PL intensity, exhibited the highest photocatalytic activity due to the synergistic effect that resulted from its high crystallinity and the optimum amount of anatase/rutile phase content, leading to the reduction of the electron-hole recombination process.

Sign in / Sign up

Export Citation Format

Share Document