Role of electron-electron scattering on ultrafast probe phenomena of photoexcited carriers in GaAs

M. J. Kann, A. M. Kriman, D. K. Ferry

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations

Abstract

Using ensemble Monte Carlo methods, coupled with a molecular dynamics (MD) approach for the carrier-carrier interaction, we investigate the ultrafast relaxation of photoexcited carriers in GaAs. The interaction of various scattering mechanisms and the dynamic screening of hot carriers in semiconductors is studied. At a density for which the GaAs is degenerate (in equilibrium), scattering out of the excitation volume is dominated in the initial tens of femtoseconds by electron-electron scattering, and the scattering rate increases with increasing density. This rate increase agrees both in magnitude and in density dependence with some recent experiments. The presence of electron-electron scattering modifies both the population transition rates and carrier densities in the satellite valleys, primarily by reshaping the energy distribution of carriers in the central valley. Intervalley processes also play a role in the initial decay and the same processes play a modified role in the picosecond-scale luminescence decay. The intervalley transition rates must be estimated carefully because the Γ-L population shift contains a significant fraction of electrons that reach the L valleys by way of the X valleys. The exchange effect further modifies the satellite valley populations and intervalley transition rates. It also reduces the rate for electrons to scatter out of the excitation volume.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsRobert R. Alfano
PublisherPubl by Int Soc for Optical Engineering
Pages98-108
Number of pages11
ISBN (Print)0819403334
StatePublished - Dec 1 1990
EventUltrafast Laser Probe Phenomena in Bulk and Microstructure Semiconductors III - San Diego, CA, USA
Duration: Mar 18 1990Mar 19 1990

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume1282
ISSN (Print)0277-786X

Other

OtherUltrafast Laser Probe Phenomena in Bulk and Microstructure Semiconductors III
CitySan Diego, CA, USA
Period3/18/903/19/90

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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