Femtosecond Carrier Dynamics in In(2)O(3) Nanocrystals

We have studied carrier dynamics in In(2)O(3) nanocrystals grown on a quartz substrate using chemical vapor deposition. Transient differential absorption measurements have been employed to investigate the relaxation dynamics of photo-generated carriers in In(2)O(3) nanocrystals. Intensity measurements reveal that Auger recombination plays a crucial role in the carrier dynamics for the carrier densities investigated in this study. A simple differential equation model has been utilized to simulate the photo-generated carrier dynamics in the nanocrystals and to fit the fluence-dependent differential absorption measurements. The average value of the Auger coefficient obtained from fitting to the measurements was gamma = 5.9 +/- 0.4 x 10(-31) cm(6) s(-1). Similarly the average relaxation rate of the carriers was determined to be approximately tau = 110 +/- 10 ps. Time-resolved measurements also revealed ~25 ps delay for the carriers to reach deep traps states which have a subsequent relaxation time of approximately 300 ps.