Multiple exciton generation and dynamics in InP/CdS colloidal quantum dots

We report measurements of multiple exciton generation and recombination in InP/CdS (core/shell) colloidal quantum dots. Ultrafast transient absorption spectroscopy was used to measure the subnanosecond charge dynamics for a range of pump fluences and for different pump photon energies. Analysis of the resulting transients was used to determine the quantum yield of multiple exciton generation, which was found to be 1.22 ± 0.01 for a pump photon energy equivalent to three times the band gap