Observation of resonant energy transfer in Au:CdS nanocomposite

Abstract

Femtosecond pump-probe measurement at 800 nm was used to analyze Au:CdS nanocomposite film. A Ti:sapphire laser with a pulse duration of 200 fs, repetition rate of 82 MHz and a center wavelength of 800 nm was used to perform pump and probe experiments. A two-photon absorption followed by a saturable absorption and recovery process, which clearly demonstrates that resonant energy transfer between CdS and Au nanocomposite systems occur with excitation at 800 nm, was shown by the time dependence of transmittance. The results show that the enhancement of the two-photon absorption coefficient in Au:CdS nanocomposite with a factor of more than 6 is observed compared to that of bulk CdS.