Meaning
Numerical algorithms used in the processing of X-ray photoelectron spectra calculate and remove the background signal generated by inelastic scattering of photoelectrons within a solid sample. This Shirley Background Subtraction provides an iterative method to determine the baseline of a spectrum where the background intensity at any energy is proportional to the integrated intensity of the photoelectrons at higher kinetic energies. The correction is essential for the quantitative analysis of oxidation states on battery electrode surfaces.
Algorithm Execution
The method utilizes an iterative mathematical formulation that adjusts the baseline step-by-step until the calculated background matches the experimental data points on both sides of the characteristic peak. Applying Shirley Background Subtraction ensures that the measured peak areas accurately represent the abundance of specific chemical species. This baseline determination is more precise than linear approximations when analyzing transition metals with complex asymmetrical peak shapes.
Application Boundary
The protocol assumes that the inelastic scattering cross-section remains constant across the narrow energy range of the analyzed peak. While highly effective for metallic and core-level transition metal peaks, the method can introduce errors if the chosen energy range is too wide or contains overlapping plasmon losses.
Data Quality
Accurate surface quantification derived from this subtraction method enables engineers to verify the chemical composition of thin-film coatings on active materials. This verification step guides the selection of coating technologies for commercial battery production.
