Electron transfer processes in double lanthanide activated YPO 4

Abstract

This work reviews electron transfer processes in double lanthanide doped YPO 4 studied using a diversity of optical techniques. The aim is to identify those transfer processes and to relate them with the location of lanthanide electron donor and lanthanide electron acceptor states within the bandgap of YPO 4. Electron transfer from the valence band to a trivalent lanthanide impurity or to the conduction band was studied by traditional single photon excitation on single lanthanide doped YPO 4. This work reports on YPO 4 doped with the electron donor Ce 3+ and co-doped with an electron acceptor Pr 3+, Er 3+, Nd 3+, Ho 3+, Dy 3+, Tm 3+, or Sm 3+ studied by means of thermoluminescence and optical stimulated luminescence techniques. The same samples were studied by pump and probe two photon spectroscopy utilizing synchrotron photons to transfer electrons from Ce 3+ to Ln 3+ defects and 445 nm laser diode to probe the concentration of created Ln 2+.