Ensemble Monte Carlo study of nonequilibrium carrier dynamics in photo-excited p-i-n structures

Light scattering from conduction electrons (or from valence holes) can give information on the time-resolved velocity distribution of nonequilibrium carriers. The experimental approach utilizes, e.g., Raman scattering from the single particles to ascertain the velocity distribution. Calculation of the distribution function through an ensemble Monte Carlo technique allows a comparison between the experiment and theory. Here, this is demonstrated with studies of a GaAs p-i-n structure embedded within cladding AlAs layers. The calculations are compared with experimental results that have recently been published on the same structure. For time scales of several hundred femtoseconds, the hot carrier transport that is probed by the single-particle Raman scattering is dominated by the transport in the Γ valley, and overshoot velocities 4–5 × 105 cm/sec are observed.