Vertical transport in GaAs/GaAlAs superlattices: Carrier density effects

Abstract With an all-optical technique, we have studied vertical transport in a 3nm/3nm GaAs/GaAlAs superlattice held at 77K. Its efficiency is strongly dependent on the photoexcitation density. This is at least partly due to a decrease of the non-radiative processes in the superlattice. The value of the ambipolar diffusion coefficient is equal to 0.65 cm 2 /s which is due to the low mobility of holes.