A study of the surface photovoltage of silicon

Abstract

The surface photovoltage of silicon has been investigated for a variety of stable silicon surfaces with a view to determining to what extent it can be used to characterize the potential of the surface. It has been found that surface trapping of photogenerated carriers results in a photovoltage signal which cannot be interpreted by the classical plasma theory to give the initial band bending at the surface, as is often assumed. It is also found that even in the absence of trapping the existence of surface photocurrents requires a modification of the plasma theory to properly represent and interpret the photovoltage.