Photoemission from thick overlying epitaxial layers of CaF2 on Si(111)

Abstract

A tunable pulsed UV laser has been used to investigate photoemission from epitaxial films on Si(111). We find that internal photoemission from the Si surface provides significant electron emission through overlayers as thick as 8000 Å. The attenuation length in the epitaxial CaF2 films is found to be 2600 Å.