Reversible Temperature Dependence in Surface-Enhanced Raman Scattering of 1-Propanethiol Adsorbed on a Silver Island Film

Abstract

Intensity of the surface-enhanced Raman scattering (SERS) of 1-propanethiol adsorbed on a silver film prepared chemically has been measured over the 15−300 K surface temperature range. A reversible change in the SERS intensity with the temperature has been observed, with the intensity at 15 K being larger than that at 300 K by a factor of ∼3. Various factors that can affect the SERS intensity such as the laser-induced change in surface morphology, adsorption and desorption, and destruction of adatoms could be eliminated as a possible cause for the observed temperature dependence. Enhancement of the Raman intensity has been calculated over the experimental temperature range based on the electromagnetic (EM) model for SERS proposed by Gersten and Nitzan. It has been found that the observed temperature dependence can be explained qualitatively with the EM model calculation.