Liquid junctions for characterization of electronic materials. II. Photoreflectance and electroreflectance of n-Si

Abstract
We compare the photoreflectance of the n‐Si/air interface with the electrolyte‐electroreflectance and electrolyte‐photoreflectance of the n‐Si/methanol interface. We observe reversible changes in line shape and in peak position of the photoreflectance signals, upon introduction of the electrolyte. The methanol proved to be the constituent that drives these changes. We have interpreted the effect of the electrolyte to be due to modifications of the kinetics of equilibration between the surface states and the space‐charge layer. This is supported by the frequency dispersion experiments in which we have demonstrated that the presence of the methanolic electrolyte causes a decrease in the relaxation time of the surface states by more than an order of magnitude.