Study of Photoemission by Using the Initial State Wave Functions Deduced by Green Function’s Method

Photoemission spectroscopy has become a very useful probe in understanding both the surface and the bulk electronic properties of metals and semiconductors. In this book chapter, the author addressed the Green's function approach of representing the initial state wavefunction, which was used to calculate photocurrent using Penn's standard formula. It was concluded that wave functions derived using Green's function approaches might be used in photoemission research for metals and semiconductors.