Some aspects of the fitting of XPS core spectra of polymers

Determination of chemical structure by means of XPS through least-squares fitting of core lines is a widely used method. We present a model for the description of XPS core lines from polymers under simultaneous consideration of the lineshape and the inelastic background. For proper consideration of the background, a model loss function with free parameters was included in the fitting process. The free parameters of the model can be found by least-squares fitting. Using this procedure, XPS core lines of many polymers can be described over a range of 25 eV, which will be demonstrated for selected polymers (PcI, PGMA, PVMK, PPG, PVME, PAA, PE). The model could be easily modified to fit other classes of materials. It will be shown how statistical analysis of the data can be used to evaluate the fitting results.