Ultrafast dynamics of non-thermal carriers in GaAs

We have studied carrier-carrier scattering in hot electron-hole plasmas, using both experiments and molecular dynamics calculations. Experiments were performed using photoluminescence via neutral acceptor recombination in GaAs. Moderate plasma densities were generated using femtosecond laser pulses at 1.7 eV. Experiments and calculations indicate that for hot non-equilibrium distributions carrier-carrier scattering can dominate the electron scattering at carrier densities as low as 8*10¹⁵cm^-3. We discuss the nature of the carrier-carrier scattering and the validity of classical molecular dynamics calculations.