LASER-DEPOSITED SILVER ISLAND FILMS - AN INVESTIGATION OF THEIR STRUCTURE, OPTICAL-PROPERTIES AND SERS ACTIVITY

Silver island films prepared by pulsed laser deposition were tested as substrates for surface enhanced raman spectroscopy. They exhibit a po sition-dependent thickness and SERS activity distribution. Cresyl Viol et and Crystal Violet were chosen as test molecules. The annealing of the films leads to coalescence of the initial island structures and th e development of longer ellipsoidal particles, which generally improve s the enhancement properties of the substrates. The dimensions of the surface structures depend on the local initial film thickness. The cha nges in tbe island shape and dimensions manifest themselves in changes in the absorption spectra. (C) 1998 John Wiley & Sons, Ltd.