Phonon-wind-driven transport of photoexcited carriers in a semiconductor quantum well

Journal Article · Sun Jan 15 00:00:00 EST 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.1862· OSTI ID:6567452

Smith, L M; Preston, J S; Wolfe, J P; Wake, D R; Klem, J; Henderson, T; Morkoc, H

The in-plane transport of photoexcited carriers in GaAsAl/sub 0.3/Ga/sub 0.7/As multiple quantum wells is measured optically with 10 ps and 4 ..mu..m resolution. The local carrier density is measured by the bleaching of the excitonic absorption line. The expansion of the photoexcited carriers following a 6-ps pump pulse is found to be a strong function of excitation power and ambient temperature. At low powers, with initial carrier densities n/sub 0/less than or equal to2 x 10/sup 11/ cm/sup -2/, the spatial distribution is well described by a single expanding Gaussian profile corresponding to an effective diffusion constant D/sub e//sub f//sub f/(n/sub 0/,T). The power and temperature dependence suggests a phonon-wind driving mechanism. At higher densities (n/sub 0/>2 x 10/sup 11/ cm/sup -2/) a narrow spatial profile appears which we attribute to ''thermal confinement'' of carriers within a phonon hot spot. After some delay, the ''confined''-carrier distribution is observed to undergo a rapid expansion. This unusual effect is attributed to the ''explosion'' of the phonon hot spot, as predicted by Kazakovtsev and Levinson.

• Research Organization: Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
• OSTI ID: 6567452
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 39:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ARSENIDES
CARRIER DENSITY
EXCITONS
GALLIUM ARSENIDES
ABSORPTION SPECTRA
CARRIER MOBILITY
DIFFUSION
GAUSS FUNCTION
OPTICAL PROPERTIES
PHONONS
SPATIAL DISTRIBUTION
TEMPERATURE DEPENDENCE
TIME RESOLUTION
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
DISTRIBUTION
FUNCTIONS
GALLIUM COMPOUNDS
MOBILITY
PHYSICAL PROPERTIES
PNICTIDES
QUASI PARTICLES
RESOLUTION
SPECTRA
TIMING PROPERTIES
360603* - Materials- Properties