Monte Carlo analysis of terahertz oscillations of photoexcited carriers in GaAsp−i−nstructures

Abstract

Pulsed terahertz emission from the electron-hole plasma excited by a femtosecond optical pulse in GaAs $p\text{\ensuremath{-}}i\text{\ensuremath{-}}n$ structures is studied by Monte Carlo simulations. The conduction band composed from $\ensuremath{\Gamma}$, $L$, and $X$ valleys, and the valence band composed from heavy, light, and split-off subbands, are considered in the simulations. The Pauli exclusion principle and the intercarrier scattering between electrons and holes are taken into account self-consistently with the time- and position-dependent carrier density and momentum distribution. Good agreement between Monte Carlo results and experimental data is obtained. The simplified hydrodynamic model of the transient dynamics of the photoexcited carriers is suggested. The proposed model accurately reproduces Monte Carlo results when the excitation is considered to be spatially uniform.