Theoretical investigation of the structure of X-ray photoelectron spectra of crystals

In the one-electron approximation general relations are obtained which determine the X-ray photoemission intensity from mono- and poly-crystalline solids. To describe the excited electron states plane waves and orthogonalized plane waves have been used. It is shown that consideration of orthogonalization terms is important when photoionization cross-sections of valence electrons are to be calculated. Results are discussed using the examples of transition metals, noble metals, semiconductors and dielectrics possessing the diamond and zinc-blende structure. The spectra from poly-crystals and single crystals of transition metals can differ markedly, but in the case of dielectrics the difference is small. Calculated X-ray photoelectron spectra of crystals are in good agreement with experimental data. To obtain detailed information of the spectrum structure, especially when transition metals are considered, the many-electron effects must be taken into account.