Knowledge Bank

Over the past decade there has been a rapid growth in the studies using optical second harmonic generation (SHG) to probe surface properties of metals and $semiconductors.1$ One of the major advantages of the technique is the ability to characterize surfaces in contact with other dense media. Our focus has been on metals and semiconductors in contact with liquids in an attempt to probe structural aspects of the surface and adjacent double layer. The studies to be described in this talk are ones which examine the rotational anisotropy in the SH response from single crystal electrode surfaces as the surface is rotated azimuthally. For the spectroscopist, studying the anisotropy in the SH response from these crystalline surfaces can provide important insight into the tensor elements which play a role in the overall SH response. Wavelength dependent studies have the potential of providing information about the electronic structure of the surface and possible surface states at the liquid/solid interface. From a more applications oriented viewpoint, the technique has the potential to provide insight into the morphological aspects of the crystalline surface and deposited overlayers. When performed in a time-resolved mode, the kinetics of deposition, surface atom reorganization and related electron transfer effects can be examined. The presentation will be an overview of these topics into which our most recent results with various single crystal surfaces in solution will be incorporated.