Photoluminescence enhancement in CdS nanoparticles by surface-plasmon resonance

To examine the influence of metal nanoparticles on the photoluminescence of semiconductors, colloidal mixtures of CdS and Au nanoparticles were prepared with different CdS/Au fractions. Compared to the cadmium-sulfide nanocrystals (quantum efficiency congruent to 7%), the CdS/Au mixtures showed enhanced luminescence properties (quantum efficiency congruent to 14%). The existence of an optimum ratio of metal to semiconductor nanoparticles for the photoluminescence intensity indicates that interactions between the metal and semiconductor nanoparticles induced by surface-plasmon resonance occur constructively at appropriate distances. (C) 2011 American Institute of Physics. [doi:10.1063/1.3615782]