Electroreflectance spectroscopy of emersed gold electrodes in the vacuum ultraviolet

Electroreflectance spectra of emersed polycrystalline gold films were measured in the vacuum ultraviolet spectral region from 6eV to 11eV. The measurements were performed using synchrotron radia- tion under high vacuum conditions. Large reflectance differences were observed for an emersion potential difference of 0.8V;The electroreflectance spectra are thought to be due primarily to electrolyte effects, with smaller contributions from the gold. Surface state optical adsorption from the predominantly (111) surface has been speculated to be one contribution. Although these measure- ments are insufficient to draw definite conclusions, they show that electroreflectance spectroscopy on emersed metal electrodes must;be considered as a possible future tool for the study of the metal-electrolyte interface; *DOE Report IS-T-1195. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy