Enhancement Of Surface Phonon Modes In The Raman Spectrum Of Znse Nanoparticles On Adsorption Of 4-Mercaptopyridine

By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm(-1)) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations. (C) 2014 AIP Publishing LLC.