Lanthanide level location in transition metal complex compounds

We will provide a method to place the levels of all trivalent lanthanides with respect to the top of the valence band and bottom of the conduction band in oxides containing transition metal complexes. The method will be applied to CaTiO3, YVO4, LaVO4, CaNb2O6, YNbO4, CaWO4, YTaO4, and LaTaO4, but in principle can be applied to any oxide containing transition metal complexes with lanthanide dopants on either rare earth or alkaline earth sites. Crucial to place the energy levels is the energy for intervalence charge transfer between a lanthanide (Pr3+Pr3+ and Tb3+Tb3+) and a transition metal ion (Ti4+,V5+,Nb5+,Mo6+,Ta5+,W6+Ti4+,V5+,Nb5+,Mo6+,Ta5+,W6+) that can be observed in luminescence excitation spectra. The quenching of Pr3+Pr3+ emission from the 3P03P0 state and of Tb3+Tb3+ emission from the 5D35D3 and 5D45D4 states provides complementary information.