Ca9Lu(PO4)7:Ce3+ and Ca9Lu(PO4)7:Pr3+ polycrystalline materials were synthesized by solid-state reaction at high temperature. The materials were characterized by powder X-ray diffraction (XRPD). The luminescence spectroscopy and the excited state dynamics of these compounds were investigated upon excitation with VUV - synchrotron radiation. Both materials showed efficient and fast 5d-4f emission upon direct VUV excitation into the 5d levels but only Ca9Lu(PO4)7:Ce3+ revealed luminescence upon excitation across the band-gap. The decay kinetics of the 5d-4f emission upon VUV intra-centre excitation is characterized by a decay time of 29 ns for Ce3+ and 17 ns for Pr3+ with no significant build-up after the excitation pulse. For the both compounds, no significant temperature dependence of the 5d-4f emission lifetime was observed within the range 8-300 K.
Interconfigurational 5d→4f luminescence of Ce3+ and Pr3+ in Ca9Lu(PO4)7
Trevisani, Mattia;PICCINELLI, FABIO;SPEGHINI, Adolfo;BETTINELLI, Marco Giovanni
2012-01-01
Abstract
Ca9Lu(PO4)7:Ce3+ and Ca9Lu(PO4)7:Pr3+ polycrystalline materials were synthesized by solid-state reaction at high temperature. The materials were characterized by powder X-ray diffraction (XRPD). The luminescence spectroscopy and the excited state dynamics of these compounds were investigated upon excitation with VUV - synchrotron radiation. Both materials showed efficient and fast 5d-4f emission upon direct VUV excitation into the 5d levels but only Ca9Lu(PO4)7:Ce3+ revealed luminescence upon excitation across the band-gap. The decay kinetics of the 5d-4f emission upon VUV intra-centre excitation is characterized by a decay time of 29 ns for Ce3+ and 17 ns for Pr3+ with no significant build-up after the excitation pulse. For the both compounds, no significant temperature dependence of the 5d-4f emission lifetime was observed within the range 8-300 K.
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