Guo, L (reprint author), Hong Kong Univ Sci & Technol, Dept Chem, Kowloon, Hong Kong.
The transient optical properties of novel PbS nanoparticles coated with 2,6-O-diallyl-beta-cyclodextrines (CDs) were studied by the femtosecond pump-probe technique. The results show that the ultrafast transient-induced absorption for the novel case. Compared to the PbS nanoparticles stabilized with polyvinyl alcohol (PVA), we find that the process for the novel case is different from the PbS(PVA). We suggest that the CDs surface modification can trap holes on the surface of PbS nanoparticles. This can induce an efficient charge separation between the PbS nanoparticles and its surface and result in an ultrafast-induced absorption for novel PbS nanoparticles. (C) 1999 Elsevier Science B.V. All rights reserved.