Accession Number : ADA138320

Title :   Theory of Surface Enhanced Raman Scattering: A Prospective View.

Descriptive Note : Technical rept.,


Personal Author(s) : Philpott,M R

PDF Url : ADA138320

Report Date : Aug 1983

Pagination or Media Count : 12

Abstract : Theoretical understanding of the origins of strong Raman signals from molecules near roughened Ag, Cu, and Au surfaces has progressed to the point where the action of two very different types of process are recognized. There is chemical enhancement that is apparent only for chemisorbed species, as for example, specifically adsorbed anions on Ag electrodes. The chemical mechanism is poorly understood, however, ingenious ideas and concepts have been advanced, including localization of electron-hole pair states and optically driven charge transfer between adsorbate and metal, to model aspects of the chemical enhancement. The second and best understood process is the enormous enhancement of the incoming and outgoing radiation fields at the surface resulting from lightening rod geometries and the excitation of localized surface plasmon modes. Calculations show that for special geometries, very high (approximately 1,000,000 - 10,000,000) enhancement factors are possible in confined regions. (Author)

Descriptors :   *Raman spectra, *Light scattering, *Molecules, *Electrochemistry, Surface reactions, Chemical reactions, Chemisorption, Anions, Silver, Electrodes, Electronic states, Holes(Electron deficiencies), Charge transfer, Excitation, Plasmons, Electrolytes, Vibrational spectra, Photons, Collisions, Copper, Gold, Raman spectroscopy

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE