The following pages are meant as an aid in understanding this technique. They are aimed at quickly explaining the fundamentals or simply refreshing your mind. According to your personal knowledge, choose which level suits you best.
An article suggested by Roland BENOIT from the CNRS of ORLEANS presenting the bases of the XPS and the various aspects of the exploitation of the spectrum . He speaks about the concept of qualitative and quantitative analysis by presenting the localization of the phenomena. It shows that the form of the spectra is also carrying information.
At the end of the article, it presents the last great evolution of this technique which is the imagery by XPS (only in French actually).
Article from Vide N°308 Volume 2/2 2003 - Spectroscopie d'électrons - XPS