Direct observation of electron velocity overshoot in an InP p-i-n nanostructure semiconductor. A subpicosecond Raman probe

We have studied the transient electron transport in an InP p-i-n nanostructure semiconductor by using subpicosecond Raman spectroscopy at T = 300 K. Both the non-equilibrium electron distribution and electron drift velocity in the regime of electron velocity overshoot have been directly measured. It is demonstrated that electron drift velocity in an InP p-i-n nanostructure is significantly larger than that in a GaAs p-i-n nanostructure sample, as a result of the larger central to satellite valley energy separation in InP.