Investigating material trends and lattice relaxation effects for understanding electron transfer phenomena in rare-earth-doped optical materials

► Rare-earth-doped materials exhibit systematic trends in electron binding energies. ► 4f electron and host band energies are presented for rare-earth-doped YAG and LaF3 materials. ► Lattice relaxation affects photoionization energies observed by different measurement methods. ► Chemical shifts of rare-earth impurities are predicted from host crystal photoemission spectra. ► A simple model predicts host-dependent trends in the rare-earth impurity binding energies.