560 research outputs found
Tuning up the performance of GaAs-based solar cells by inelastic scattering on quantum dots and doping of AlyGa1-ySb type-II dots and AlxGa1-xAs spacers between dots
We used AlGaSb/AlGaAs material system for a theoretical study of photovoltaic
performance of the proposed GaAs-based solar cell in which the type-II quantum
dot (QDs) absorber is spatially separated from the depletion region. Due to
inelastic scattering of photoelectrons on QDs and proper doping of both QDs and
their spacers, concentrated sunlight is predicted to quench recombination
through QDs. Our calculation shows that 500-sun concentration can increase the
Shockley-Queisser limit from 35% to 40% for GaAs single-junction solar cells.Comment: 8 pages, 7 figures; Contributed paper to SPIE Photonics West, San
Francisco, CA, USA, February 201
Two Photon Exchange for Exclusive Pion Electroproduction
We perform detailed calculations of two-photon-exchange QED corrections to
the cross section of pion electroproduction. The results are obtained with and
without the soft-photon approximation; analytic expressions for the radiative
corrections are derived. The relative importance of the two-photon correction
is analyzed for the kinematics of several experiments at Jefferson Lab. A
significant, over 20%, effect due to two-photon exchange is predicted for the
backward angles of electron scattering at large transferred momenta
Monte Carlo generator ELRADGEN 2.0 for simulation of radiative events in elastic ep-scattering of polarized particles
The structure and algorithms of the Monte-Carlo generator ELRADGEN 2.0
designed to simulate radiative events in polarized ep-scattering are presented.
The full set of analytical expressions for the QED radiative corrections is
presented and discussed in detail. Algorithmic improvements implemented to
provide faster simulation of hard real photon events are described. Numerical
tests show high quality of generation of photonic variables and radiatively
corrected cross section. The comparison of the elastic radiative tail simulated
within the kinematical conditions of the BLAST experiment at MIT BATES shows a
good agreement with experimental data.Comment: 36 pages, 7 figures, 3 table
Photoinduced magnetism in the ferromagnetic semiconductors
We study the enhancement of the magnetic transition temperature due to
incident light in ferromagnetic semiconductors such as EuS. The photoexcited
carriers mediate an extra ferromagnetic interaction due to the coupling with
the localized magnetic moments. The Hamiltonian consists of a Heisenberg model
for the localized moments and an interaction term between the photoexcited
carriers and the localized moments. The model predicts a small enhancement of
the transition temperature in semi-quantitative agreement with the experiments.Comment: 5 pages, 5 figure
Radiative corrections to the lepton current in unpolarized elastic -interaction for fixed and scattering angle
The kinematical difference between the description of radiative effects for
fixed vs a fixed scattering angle in the elastic lepton-proton
()-scattering is discussed. The technique of calculation as well as
explicit expressions for radiative corrections to the lepton current in
unpolarized elastic -scattering for these two cases are presented without
using an ultrarelativistic approximation. A comparative numerical analysis
within kinematic conditions of Jefferson Lab measurements and MUSE experiment
in PSI is performed.Comment: 12 pages, 5 figures, published in European Physical Journal A Topical
Issue 'An Experimental Program with Positron Beams at Jefferson Lab
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