An experiment was designed to measure sum-frequency generation (SFG) spectra in both reflection and transmission. The result from an octadecyltrichlorosilane monolayer on a substrate reveals that while the resonant spectra in the two geometries both originate from the surface monolayer, the bulk substrate has a significant contribution to the nonresonant background in the transmitted spectra. Study of a polyethylene film also shows that the bulk contribution to the SFG spectra is only significant for the transmission geometry, exhibiting a resonant mode not observable in the reflected spectra.
|Number of pages
|Journal of Physical Chemistry B
|Published - 2000 Apr 13
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry