Level location and spectroscopy of Ce3+, Pr3+, Er3+, and Eu2+ in LaBr3

The spectroscopic properties of LaBr3 doped with Ce3+, Pr3+, Er3+, and Eu2+ under ultraviolet excitation are reported. LaBr3 host excitation and emission, 4f-5d excitation and emission of Ce3+ and Eu2+, and charge transfer from the valence band to Pr3+ and Er3+ are observed. This experimental information is combined with an empirical model to estimate the position of the lowest 4f and lowest 5d state relative to the conduction band and valence band for each divalent lanthanide ion in LaBr3. Existing literature data is used to determine the location of the lowest 4f and lowest 5d state for each trivalent lanthanide.