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

Samples of the Ca 3 Sc 2 Si 3 O 12 (CSS) host singly doped with Eu 2+ or Yb 3+ , doubly doped with Eu 2+ and Yb 3+ , and triply doped with Ce 3+ , Eu 2+ and Yb 3+ were synthesized by a sol–gel combustion process under reducing conditions. Unlike previous reports of Eu 2+ →Yb 3+ 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 Yb 3+ is further enhanced by co‐doping with Ce 3+ in addition to Eu 2+ . The quantum efficiencies of the doped materials range between 9 % and 93 %.