Optical response of thiosalicylic-capped CdS nanocrystals to terbium ions

The effects of terbium ion addition on the optical spectra of CdS nanocrystals capped with thiosalicylic acid were investigated by means of absorption and steady-state photoluminescence spectroscopy. Upon terbium addition, the CdS absorption was modified around the first exciton peak while the CdS photoluminescence experienced selective enhancing and quenching processes. The results indicated that, most probably, the two types of changes are decoupled. The interpretation considered the key role played by the capping ligand in the optical response of nanocrystals to the lanthanide ions.