Ultrafast processes in InAs/GaAs quantum dot based electro-absorbers

In this study we perform a detailed investigation of the ultrafast processes which govern the intradot recovery dynamics of a QD InAs/GaAs structure under reverse bias condition by means of the single and two colour pump-probe technique. By studying the GS and ES recoveries as a function of reverse bias voltage and fitting the experimental results with a simple rate equation model for the intradot carrier dynamics we have illustrated the dominance of Auger mediated recovery when the ES is initially populated while phonon mediated recovery dominates for the GS case. This provides opportunities for the design of the next generation of electro-absorbing devices based on QD materials.