Upper satellite conduction band population dynamics in GaAs measured by femtosecond UV pump - IR probe absorption spectroscopy

Abstract

Over the past twenty years hot electron dynamics have been studied in the central (i.e., k=0), Γ, and satellite (i.e., k≠0), L and X6, lower conduction band valleys in bulk GaAs and quantum wells using ultrafast laser spectroscopy.1-4 A Monte Carlo calculation has shown that the satellite, X7, upper conduction band valley plays an important role in the high-field transport properties of GaAs.5 We will present for the first time an experimental study of the intervalley relaxation dynamics of a hot electron population in the satellite, X7, upper conduction band valley in GaAs using time-resolved UV pump-IR probe absorption spectroscopy.