Field-induced electron transport and phonon dynamics in a GaAs-based p-i-n nanostructure: A subpicosecond time-resolved Raman probe

Electron transport and phonon dynamics in a GaAs-based p-i-n nanostructure under the application of an electric field have been studied by time-resolved Raman spectroscopy at T=80 K. The time evolution of electron density, electron distribution, electron drift velocity, and LO-phonon population has been directly measured with subpicosecond time resolution. Our experimental results show that, for a photoexcited electron-hole pair density of n congruent to 10(17) cm(-3), the effects of the drifting of electrons and electron intervalley scattering processes govern electron transport properties as well as the LO-phonon dynamics. All of the experimental results are compared with ensemble Monte Carlo simulations and satisfactory agreement is obtained.