Effect of Surface Current on Photoelectron Emission from Mica

Abstract

The photoelectron emission from mica surface was investigated using UV irradiation. It has been revealed that such emission has close relation to the surface structure as well as the surface conduction characteristics. In order to study the relationship between the photoelectron emission and the conduction mechanism of the mica surface, the photothreshold of the electron emission from the surface was measured for the cleaved mica (Muscovite) surface treated by FAB, i.e., Fast Atom Bombardment, using a low-energy photoelectron counter under atmospheric conditions.
While the photothreshold of the FAB-treated mica varied from 5.0 eV to 5.8 eV, no variation was observed for the photothreshold of the untreated mica surface. This difference was interpreted by the difference of carriers for the surface current and the photocurrent.
The results of the observation suggest that the surface states of mica can play an important role in the electronic conduction of the surface as well as the photoelectron emission therefrom.