相关论文: Imaging ambipolar diffusion of photocarriers in Ga…
The ambipolar carrier diffusion in bulk GaAs is studied by using an ultrafast pump-probe technique with a high spatial resolution. Carriers with a point-like spatial profile are excited by a tightly focused pump laser pulse. The…
The diffusion of photo-generated holes is studied in a high-mobility mesoscopic GaAs\ channel where electrons exhibit hydrodynamic properties. It is shown that the injection of holes into such an electron system leads to the formation of a…
The diffusion of electron-hole pairs, which are excited in an intrinsic graphene by the ultrashort focused laser pulse in mid-IR or visible spectral region, is described for the cases of peak-like or spread over the passive region…
Room temperature electronic diffusion is studied in 3 mum thick epitaxial p+ GaAs lift-off films using a novel circularly polarized photoluminescence microscope. The method is equivalent to using a standard optical microscope and provides a…
We report ultrafast transient-grating experiments on heavily p-type InP at 15 K. Our measurement reveals the dynamics and diffusion of photoexcited electrons and holes as a function of their density n in the range 2E16 to 6E17 cm-3. After…
The effects of ambipolar diffusion on the linear stability of weakly ionised accretion discs are examined. Earlier work on this topic has focused on axial magnetic fields and perturbation wavenumbers. We consider here more general field and…
In p+ GaAs thin films, the effect of photoelectron degeneracy on spin transport is investigated theoretically and experimentally by imaging the spin polarization profile as a function of distance from a tightly-focussed light excitation…
Inter-band photo-excitation of electron states with the twisted photons in GaAs, a direct band-gap bulk semiconductor, is considered theoretically. Assuming linearity of the quantum transition amplitudes and applying Wigner-Eckart theorem,…
Cubic boron arsenide (BAs) is promising for microelectronics thermal management due to its high thermal conductivity. Recently, its potential as an optoelectronic material is also being explored. However, it remains challenging to measure…
The results of investigation of bulk GaAs photoluminescence are presented taken from near-surface layers of different thicknesses using for excitation the light with the wavelengths which are close but some greater than the excitonic…
A simple yet precise optical technique for measuring the ambipolar carrier mobility in semiconductors is presented. Using tightly focused Gaussian laser beams in a photo-reflectance system, the modulated reflectance signal is measured as a…
In order to determine the role of non-thermal transport of hot carriers which is decisive for the dissipation of energy in condensed matter we performed time-resolved broadband femtosecond transient reflectivity measurements on $7-197…
The results of investigation of bulk GaAs photoluminescence are presented taken from near-surface layers of different thicknesses using for excitation the light with the wavelengths which are close but some greater than the excitonic…
Despite its potential in the fields of optoelectronics and topological insulators, experimental electronic band structure studies of Bi-doped GaAs are scarce. The reason is the complexity of growth which tends to leave bulk and in…
Defect centers in GaN emerge as bright sources of single-photons which recently have been demonstrated to optically interface a localized spin. However, the structure and composition of these defects as well as their efficient excitation…
We report here a general theory describing photoelectron transportation dynamics in GaAs semiconductor photocathodes. Gradient doping is incorporated in the model through the inclusion of directional carrier drift. The time-evolution of…
We determine the diffusion length of excess carriers in GaN by spatially resolved cathodoluminescence spectroscopy utilizing a single quantum well as carrier collector or carrier sink. Monochromatic intensity profiles across the quantum…
Previous treatments of ambipolar diffusion in star-forming molecular clouds do not consider the effects of fluctuations in the fluid fields about their mean values. This paper generalizes the ambipolar diffusion problem in molecular cloud…
It is shown, that diffusion of saturated gain (e.g. diffusion of population inversion in lasers) causes, and/or enhances a modulational instability of generated light field. In case of a subcritical system (e.g. a laser with saturable…
Starting from the Heisenberg-Euler effective Lagrangian, we determine the photon current and photon polarization tensor in inhomogeneous, slowly varying electromagnetic fields. To this end, we consider background field configurations…