Time-Dependent SERS Study: An Implication of SERS Mechanism
Surface-enhanced Raman scattering (SERS) is highly sensitive to adsorbed species on roughened silver surfaces. It is well-known that two kinds of roughness are necessary for SERS; i.e. large scale roughness of an order of 100 A and small scale roughness of an order of atoms. The former is known to give large electromagnetic field enhancement. We studied recently the contribution of the latter roughness, small scale roughness, formed by the electrochemical treatment and concluded that the latter is originated from atomic scale metal clusters. It is exceedingly important to reveal the role of the clusters.