Observation of large electron drift velocities in InN by ultrafast Raman spectroscopy

Abstract

Electron transport in an InN film grown on GaN has been studied by transient Raman spectroscopy at T=300K. Our experimental results demonstrate that under the subpicosecond laser excitation and probing, electron drift velocity of carriers in the Γ valley can exceed its steady-state value by as much as 40%. Electron velocities have been found to cut off at around 2×108cm∕s, significantly larger than those observed for other III-V semiconductors, such as GaAs and InP. These experimental results have been compared with ensemble Monte Carlo simulations and good agreement has been obtained.