Direct measurement of electron capture in InAs/Inalas quantum dots

Promising quantum-dot devices such as lasers and infrared photodetectors have lead to an intensive study of the optical properties of quantum dots. The physics of carrier dynamics in quantum dots is of particular importance for devices especially because of a drastic slow-down of the relaxation is expected due to the discrete nature of the electronic energy states (phonon bottleneck effect). This paper discusses femtosecond pump-probe experiments in the mid-infrared range where, in contrast to previous experiments, the electron dynamics is clearly separated from that of holes.