Carrier Dynamics in Nanostructured Materials

Fig. 1. Schematic illustration of charge carrier relaxation in semiconducting nanoparticles and the pump-probe scheme for monitoring the carrier dynamics. The long solid line with upward arrow indicates excitation and the short solid lines with upward indicate probe of the conduction band, shallow and deep trap states, and valence band, respectively. The curved lines with downward arrows indicates different relaxation process: (1) electronic relaxation within the conduction band, (2) trapping into shallow trap (ST) and deep trap (DT) states and further trapping from ST to DT, (3) band edge electron-hole recombination, (4) trapped electron-hole recombination, (5) exciton-exciton annihilation.