Heterogeneity of the electron-trapping kinetics in CdSe nanoparticles.

The kinetics of electron trapping in CdSe nanoparticles are examined from 0.5 ps to 1.8 ns. The ensemble kinetics fit a slow power law, but two-dimensional measurements show that the decay of each nanoparticle is exponential. A model is proposed in which defect sites provide a gateway for surface trapping and are randomly distributed on the surface. The electric field from the particle's dipole moment creates the observed heterogeneity in rates.