Temporal evolution of capped cadmium sulfide nanoparticles

Cadmium sulfide nanoparticles capped with thioglycolic acid as an organic ligand were synthesized by solution chemistry. Temporal evolution was studied by optical absorption, fluorescence, TEM, FTIR and x-ray diffraction measurements to understand the growth and stability of nanocrystals/ligand composites. The results suggest that besides being a good capping agent, thioglycolic acid also acts as an effective passivating ligand for electronically active surface states of CdS nanoparticles. Such binding quenches surface recombination and improves excitonic (band-to-band) recombination. This makes CdS nanoparticles an attractive material for certain applications wherein surfaces states are to be eliminated