LOW-DIMENSIONAL DISPERSIVE TRANSPORT AT NANOCRYSTAL INTERFACES

Two-color picosecond pump-probe measurements in semiconductor nanocrys tallite doped glasses reveal non-exponential decay of photoexcitations . The temperature dependence of the decay is examined and discussed wi thin the framework of continuous-time random walk models for the trans port of photocarriers among localized trap sites. This analysis sugges ts that both dispersive and hopping transport of photocarriers in lowe r dimensions are involved in the relaxation of these nanoscale systems . Studies of larger nanocrystallites, where well defined facets are ob served, reveal that crystal edges may play an important role in determ ining the dimensionality of the transport.