Surface–plasmon-coupled photoluminescence from CdS nanoparticles with Au films

The enhancement of surface–plasmon-coupled photoluminescence from CdS nanoparticles was examined for various thicknesses of sputtered Au films. The improved luminescence with thickness control of Au correlated well with the increased density of surface–plasmon states, which was modified by the plasmon-dispersion relation at the planar Au/PMMA interface. By annealing the Au films to form a rough surface morphology, the emission in the CdS nanoparticles was further enhanced by the improved excitation and coupling of the surface–plasmon modes.

► The surface–plasmon effects on the photoluminescence (PL) of CdS nanoparticles.
► The PL enhancement matches well with the density of surface–plasmon states.
► Further enhanced PL emission was observed with rough Au surface.
► The contribution from the prolonged optical-path lengths was excluded.