Hot-electron relaxations and hot phonons in GaAs studied by subpicosecond Raman scattering

Journal Article · Fri Feb 15 04:00:00 EST 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.4158· OSTI ID:5762554

Kim, D; Yu, P Y ^[1]

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1. Department of Physics, University of California, Berkeley, California 94720 (US) Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720

We have utilized subpicosecond laser pulses to excite and probe hot electrons and nonequilibrium longitudinal-optical (LO) phonons in bulk GaAs by Raman scattering. We find that the photoexcited hot electrons cool at a rate much faster than predicted by {ital intra}valley scattering of LO phonons via the Froehlich interaction. On the other hand, this fast cooling rate can be accounted for satisfactorily by {ital inter}valley scattering. As a result of this very rapid cooling, the temperature of the hot LO phonons generated by the hot electrons temporarily overshoots the electron temperature. From the electron cooling curve and the dependence of the hot-phonon temperature on the excited-electron density, we determined the deformation potential for scattering between the {Gamma} and {ital L} conduction-band valleys in GaAs.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5762554
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 43:5; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ARSENIC COMPOUNDS
ARSENIDES
ELECTROMAGNETIC RADIATION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
LASER RADIATION
PHONONS
PLASMONS
PNICTIDES
QUASI PARTICLES
RADIATIONS
RAMAN SPECTRA
SCATTERING
SPECTRA
SPECTRAL SHIFT