open access

https://hdl.handle.net/2115/50222

Size-Dependent Carrier Dynamics in CdS Nanoparticles by Femtosecond Visible-Pump/IR-Probe Measurements

英語

2006-07-27

American Chemical Society

Journal of Physical Chemistry B

110(29)

14192-14197

Ultrafast photoexcited carrier dynamics in CdS nanoparticles prepared by an AOT/n-heptane reversed micelle system were investigated by a femtosecond visible-pump/mid-IR probe technique. A mid-IR probe beam was found to mainly probe the ultrafast dynamics of photoexcited electrons in the conduction band. Dispersions of CdS nanoparticles with 8 different mean diameters from 2.9 to 4.1 nm were prepared by tuning the mole ratio between water and AOT (W = [H2O]/[AOT]) in the reversed micelle systems. The excited state lifetime strongly depended on the mean size of CdS nanoparticles with a maximum around a mean diameter of 3.5 nm. This result was explained by considering the balance between the carrier recombination rates via surface states and those via interior states. The relationship between the excited state lifetime and the size of CdS nanoparticles was drastically changed when the surface was terminated by thiol molecules.

学術雑誌論文

Version of Record

1520-6106

1520-5207