Femtosecond carrier relaxation dynamics in colloidal CdSe quantum dots are measured which focus on the early time dynamics for different initial excitonic states. Selecting the initial excitonic states produces a clear influence upon the early time dynamics. The difference between the dynamics when initially populating different excitonic states provides a direct measurement of excitonic relaxation times in strongly confined colloidal semiconductor quantum dots with specificity to electrons and holes. These results furthermore show state specific biexciton interactions.

• Received 9 August 2006

DOI:https://doi.org/10.1103/PhysRevB.74.235328