In-plane transport of photoexcited carriers in GaAs quantum wells

Journal Article · Sun Nov 15 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.13461· OSTI ID:6916362

Yoon, H W; Wake, D R; Wolfe, J P ^[1]; Morkoc, H ^[2]

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1. Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)
2. Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

We have measured the picosecond-time-resolved in-plane motion of carriers in a multiple quantum well by a spatially scanned pump-probe technique at bath temperatures between 8.5 and 60 K. The effective ambipolar diffusivity measured from the spatial expansion of a nonequilibrium carrier distribution is found to increase with pump power, i.e., carrier density. We believe that this effect is in part due to the formation of a degenerate semiconductor plasma and to screening of scattering centers. An increase in the diffusivity is observed with the change in the bath temperature from 8.5 to 60 K that is consistent with a simple impurity-limited scattering model. The diffusivity at 0--200 ps is found to increase with the incident photon energy, while the diffusivity measured at 500 ps remains relatively constant with increasing photon energy. The decrease in the expansion rate with time is ascribed to the decreasing kinetic energies of the carriers.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6916362
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:20; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CARRIER DENSITY
CHARGE TRANSPORT
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
EXCITATION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
IRRADIATION
LASER RADIATION
PNICTIDES
PULSED IRRADIATION
RADIATIONS
TEMPERATURE RANGE
TEMPERATURE RANGE 0013-0065 K