Enhanced Raman signals in thin solid films formed from fullerene, copperphthalocyanine, or perylene derivates and incorporated metal clusters

Surface enhanced Raman spectroscopy (SERS) experiments have been carried out in thin organic films with incorporated metal clusters. Copperphthalocyanine, N,N′-dimethyl-3,4,9,10-perylenedicarboximid (MPP) and fullerene have been used as matrix materials, while the clusters were formed from silver, gold, or copper. In these systems, maximum Raman cross-section enhancement values of the molecular matrix have been found to be around 70. The effects have been attributed to resonant excitation of local plasmon modes in the metal clusters. The Raman spectra are discussed with respect to spectral shape and Raman intensity enhancement in terms of a semiclassical microscopic SERS approach. In particular, the different effects of homogeneous and inhomogeneous plasmon line broadening on the SERS efficiency are extensively discussed.