Γ to <i>X</i> transport of photoexcited electrons in type II GaAs/AlAs multiple quantum well structures

Abstract

We report novel femtosecond time-resolved measurements performed on staggered type II GaAs/AlAs multiple quantum well structures. Photoexcited electrons were determined to transfer from the Γ valley of the GaAs layers to the X valleys of the AlAs in 100 and 400 fs for 8- and 11-monolayer-thick GaAs samples, respectively.