Femtosecond Carrier Dynamics in In2O3Nanocrystals
1 Department of Physics, Research Centre of Ultrafast Science, University of Cyprus, P.O. Box 20537, Nicosia, 1678, Cyprus
2 Department of Mechanical and Manufacturing Engineering, Materials Science Group, Nanostructured Materials and Devices Laboratory, University of Cyprus, P.O. Box 20537, Nicosia, 1678, Cyprus
Nanoscale Research Letters 2009, 4:526-531 doi:10.1007/s11671-009-9275-0Published: 27 February 2009
We have studied carrier dynamics in In2O3nanocrystals 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 In2O3nanocrystals. 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 γ = 5.9 ± 0.4 × 10−31 cm6 s−1. Similarly the average relaxation rate of the carriers was determined to be approximately τ = 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.