Nano Express

Nanoscale Research Letters

, Volume 4, Issue 6, pp 526-531

Open Access This content is freely available online to anyone, anywhere at any time.

Femtosecond Carrier Dynamics in In2O3 Nanocrystals

  • Andreas OthonosAffiliated withDepartment of Physics, Research Centre of Ultrafast Science, University of Cyprus Email author 
  • , Matthew ZervosAffiliated withDepartment of Mechanical and Manufacturing Engineering, Materials Science Group, Nanostructured Materials and Devices Laboratory, University of Cyprus
  • , Demetra TsokkouAffiliated withDepartment of Physics, Research Centre of Ultrafast Science, University of Cyprus

Abstract

We have studied carrier dynamics in In2O3 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 In2O3 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 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.

Keywords

In2O3 nanocrystals Carrier dynamics Femtosecond differential absorption spectroscopy Auger coefficient