Unique Spectral Overlap and Resonant Energy Transfer between Europium(II) and Ytterbium(III) Cations: No Quantum Cutting.

Samples of the Ca3 Sc2 Si3 O12 (CSS) host singly doped with Eu2+ or Yb3+ , doubly doped with Eu2+ and Yb3+ , and triply doped with Ce3+ , Eu2+ and Yb3+ were synthesized by a sol-gel combustion process under reducing conditions. Unlike previous reports of Eu2+ →Yb3+ energy transfer in other systems, the energy transfer is resonant in the CSS host and the transfer efficiency reaches 100 % for lightly doped samples. The transfer mechanism is multipolar rather than electron transfer for the sample compositions employed herein. The emission intensity of Yb3+ is further enhanced by co-doping with Ce3+ in addition to Eu2+ . The quantum efficiencies of the doped materials range between 9 % and 93 %.