Inelastic electron background function for ultraviolet photoelectron spectra

We present a simple approach to the determination of inelastic backgrounds in low-energy electron spectra such as UPS that fits the spectra much better than does the iterative integral background which is generally used in higher-energy spectroscopies such as XPS. Including the secondary-electron cascade process explicitly yields a non-iterative function that gives a good description of the inelastic background in UPS spectra from transition-metal oxides for low photon energies. For photon energies above about 40 eV but below the XPS region, the background function is not always able to adequately model the spectra; the discrepancy cannot be removed by a more sophisticated treatment of the electron scattering function.