Automated information compression of XPS spectrum using information criteria

•We developed an automated method for XPS analysis based on the active Shirley method.•A lot of initial fitting models were searched by changing a degree of smoothing.•The goodness of optimized models was ranked by information criteria.•The model selected by BIC is close to the result of peak fitting by XPS experts. We developed and implemented a fully automated method to perform X-ray photoelectron spectroscopy (XPS) spectral analysis based on the active Shirley method and information criteria. Our method searches a large number of initial fitting models by changing the degree of smoothing, and then optimizes the peak parameters and background parameters to obtain a large number of fitting results. The goodness of those optimized models is ranked using information criteria. As a result of applying this algorithm to measured XPS spectra, we found that, using the Bayesian information criterion (BIC), a simple model with reasonably good agreement and a moderate number of peaks was selected. The model selected by the BIC was close to the result of peak fitting performed by XPS analysis experts.