Carrier relaxation in (GaIn)As quantum dots

Time‐resolved photoluminescence experiments are performed to study carrier relaxation in strain‐induced (GaIn)As quantum dot structures. We observe a sub‐picosecond onset of the photoluminescence from the lowest quantum‐dot electron–hole transition after optical excitation of higher‐energetic barrier states. This shows that carrier capture into the quantum‐dot ground state can be extremely fast at high electron–hole densities. The recombination lifetime of the lowest quantum‐dot transition and the interlevel relaxation time are extracted from the decay of the photoluminescence transients.