Carrier dynamics in self-assembled ErAs nanoislands embedded in GaAs measured by optical-pump terahertz-probe spectroscopy

We use optical-pump terahertz (THz)-probe spectroscopy to study carrier dynamics in self-assembled ErAs nanoislands embedded in GaAs and deposited in a superlattice structure. Measurements are performed at several pump fluences on samples with different superlattice periods, enabling a determination of the time-dependent conductivity. Subpicosecond carrier capture times are obtained, indicating the potential of these devices as time-domain THz detectors with performance comparable to low-temperature grown GaAs and superior control of material parameters.