Configuration coordinate energy level diagrams of intervalence and metal-to-metal charge transfer states of dopant pairs in solids

摘要: Configuration coordinate diagrams, which are normally used in a qualitative manner for the energy levels of active centers phosphors, quantitatively obtained here intervalence charge transfer (IVCT) states mixed valence pairs and metal-to-metal (MMCT) heteronuclear pairs, solid hosts. The procedure relies on vibrational frequencies excitation energies single-ion centers, differences between ion–ligand distances donor acceptor, attainable empirically or through ab initio calculations. configuration diagrams Yb2+/Yb3+ mixed-valence pair Yb-doped YAG Ce3+/Yb3+ Ce,Yb-codoped YAG, described. They drawn from empirical data single-ions their usefulness is discussed. first diagram suggests that IVCT may play an important role quenching Yb3+ emission it provides details mechanism. second supports interpretation recently given Ce3+ to via MMCT Ce4+–Yb2+ state details. analyses two suggest formation after Ce3+-to-Yb3+ MMCT, responsible temperature excited (4f → 5d) absorption YAG.