Phonon-wind-driven transport of photoexcited carriers in a semiconductor quantum well

The in-plane transport of photoexcited carriers in GaAsAl0.3Ga0.7As multiple quantum wells is measured optically with 10 ps and 4 μm resolution. The local carrier density is measured by the bleaching of the excitonic absorption line. The expansion of the photoexcited carriers following a 6-ps pump pulse is found to be a strong function of excitation power and ambient temperature. At low powers, with initial carrier densities n0≤2×1011 cm-2, the …