Journal Raman Spectroscopy

SERS spectra were observed from molecules adsorbed on silver and on various semiconductor surfaces on to which an Ag island film had been evaporated. Because of the observed spectral differences between these spectra, it could be confirmed that the observed Raman scattering arises from molecules adsorbed on semiconductors and not on the Ag film. With this method, Raman scattering from the surface of the semiconductors is enhanced because the discontinuous Ag film produces a large electromagnetic enhancement at each Ag particle. Therefore, the surface sensitivity of the SERS effect at metal surface was used to study molecules adsorbed on the semiconductors. It was not possible to detect Raman scattering from surfaces without the deposited Ag film because the vibrational spectra of molecules adsorbed on the semiconductor surfaces were too weak to be detected. These results prove that adsorbed species on semiconductor surface can be detected by SERS spectroscopy by coating the surface with a discontinuous Ag film.