Electron velocity overshoot and nonequilibrium phonons in a GaAs-based p-i-n nanostructure studied by transient subpicosecond Raman spectroscopy

Transient subpicosecond Raman spectroscopy has been used to study electron velocity overshoot as well as nonequilibrium phonons in a GaAs-based p-i-n nanostructure under the application of high electric fields. Both electron distribution functions and nonequilibrium phonon populations were directly obtained in the velocity overshoot regime for a variety of electric field intensities and for different electron densities. All of our experimental results are compared with ensemble Monte Carlo calculations and good agreement is achieved.