Time-resolved electroluminescence spectroscopy of resonant tunneling in GaAs-AlAs superlattices

The carrier transport through a resonantly coupled GaAs-AlAs superlattice is investigated by time-resolved electroluminescence. Ultrashort current pulses are used to electrically inject electrons and holes into an externally biased superlattice. The time evolution of the emitted light is recorded, which allows us to directly monitor the temporal development of the carrier transport and the associated dynamics of the electric field. At resonance a strong reduction of the initial rise time of the electroluminescence signal is observed.