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

Samples of the Ca3Sc2Si3O12 (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 %. Gewinnung von Sonnenenergie: Einfach mit Eu2+ oder Yb3+, doppelt mit Eu2+ und Yb3+ und dreifach mit Ce3+, Eu2+ und Yb3+ dotierte Ca3Sc2Si3O12(CSS)‐Wirtgitter wurden in einem Sol‐Gel‐Verbrennungsprozess synthetisiert. Das dreifach dotierte System wandelt Sonnenenergie in eine Nahinfrarot‐Emission des Yb3+‐Ions um (dd=Dipol‐Dipol‐, dq=Dipol‐Quadrupol‐Wechselwirkungen; ET=Elektronentransfer).