Subpicosecond timescale carrier dynamics in GaInAsSb/AlGaAsSb double quantum wells emitting at 2.3 μm

We report the results of an extensive optical investigation by continuous-wave and time resolved photoluminescence experiments on double GaInAsSbAlGaAsSb quantum wells emitting at 2.3 μm at room temperature. We have found that, at low temperature (<70 K), the recombination is dominated by excitons trapped in disorder and interface defects. Whereas, at higher temperature, free-exciton recombination occurs. The observed temperature dependent photoluminescence quenching is ascribed to the ionization of bound exciton at low temperatures, while thermoionic emission of the hole out of the quantum well dominates photoluminescence quenching at high temperatures. The experimental results are supported by theoretical calculations.