Results of experimental and theoretical investigations in charge transfer transitions, scintillators and Eu2+ based phosphors

A brief overview of recent results obtained in scintillator and phosphors are presented. Four topics, that are at the center of considerable research, and which are important from both fundamental and practical point of view, are chosen. The identification and behavior of ligand-to-RE3+ (RE3+ = rare earth) charge transfer transition when the ligand ions are halides and N3− is reviewed. The reasons for the high light yield of the LuI3:Ce3+ scintillator is investigated theoretically and a new channel of energy transfer to excitons and directly to the Ce3+ ion identified. The prospect of increasing the light yield of Ce3+ based scintillators by the Pr3+ ion is discussed. Finally, the remarkable luminescence of octahedrally coordinated Eu2+ ion in Cs2M2+P2O7 (M2+ = Ca, Sr) is discussed.