Femtosecond inter- and intra-band spectroscopy of semiconductor quantum dots

Summary form only given. Due to a large energy level spacing and an enhanced surface-to-volume ratio, carrier dynamics in strongly-confined semiconductor nanocrystals (NCs) are significantly different from those in bulk materials. The large level separation has been predicted to significantly inhibit energy relaxation due to a phonon bottleneck which, however, has been argued against by recent experiments. The relaxation of carriers from the lowest quantized states in NCs can be significantly faster than for radiative decay, which is due to enhancement of non-radiative processes associated, e.g., with surface trapping.