Mechanisms and dynamics of optical nonlinearities in semiconductor nanocrystals

In this paper, we discuss the dynamics of carrier recombination in semiconductor nanoparticles embedded in a glass matrix, forming the so-called semiconductor-doped glasses. We observe that carrier recombination may be made faster by photodarkening and, at high excitation intensity, by Auger processes. We also discuss the mechanisms of the resonant optical Kerr effect in these materials. It is shown to be comprised of a fast component due to free carriers in particles without traps and of a slow one due to trapped carriers in particles with traps. The figure of merit associated with the fast component decreases when the particle size decreases.