Luminescence and Energy-Transfer Mechanism in SrSi2O2N2:Ce3+,Eu2+ Phosphors for White LEDs.

A series of Ce³⁺ and Eu²⁺ co-doped SrSi₂O₂N₂ phosphors, whose features qualify them for consideration in white-light UV or blue light-emitting diodes (LEDs), was synthesized via a high temperature solid-state reaction under a reductive atmosphere. The dependence of luminescence properties of the produced powders on the Concentration of an activator (Eu²⁺) and a coactivator (Ce³⁺) was investigated. The experimentally recorded luminescence spectra and the calculations of the efficiency of energy transfer from Ce³⁺ to Eu²⁺ and the critical distance between Ce³⁺ and Eu²⁺ suggest a resonance-type energy-transfer mechanism from Ce³⁺ to Eu²⁺ due to dipole-dipole interactions. [ABSTRACT FROM AUTHOR]