the cdse qds under uv illumination scans of the pl signal show up to 10 times higher intensity on the au nanoparticle arrays in both single and double layer areas than in the bare si stripes with the same qd density see fig1 a 11c this value is times higher than that previously reported for cdse zns core shell qds and cdse qds on disordered 15 nm au nanoparticle assemblies with optimized dielectric spacer thickness fig8 d shows the raman spectra of cdse qds collected in different spots of the inset small box in fig8 b the top curve is the sers signal of the cdse qds on the au monolayer and the bottom curve is the signal on bare silicon substrate both spectra were collected under the same acquisition conditions in the spots shown by arrows in fig8 d after extraction of the background the raman peak at 207 cm u2212 1 of the cdse qds deposited on the au array is 500 times higher than that on silicon this characteristic peak corresponds to the cdse longitudinal optical phonon mode u2014 lo 1 also the second harmonic of this vibrational mode u2212 2lo 1 near 414 cm u2212 1 is clearly seen on au nanoparticles but is not resolved for qds on silicon the qd raman peaks in fig8 d are more pronounced than those measured in commercial plasmonic arrays of inverted pyramids klarite substrates excited at the same 514 nm wavelength the 2d raman scan image at 207 cm u2212 1 inset in fig8 d clearly visualizes the enhancement of.