This work concerns a novel blue emitting LED phosphor activated by Eu2+. It was found that this luminescent material can be efficiently pumped by near UV or UV-A radiation sources while it exhibits a high quantum yield at a doping level between 0.3 and 3.0%. More impressively, this material has a very high quenching temperature T1/2 and will thus be applicable on-chip in high power phosphor converted LEDs or even in laser diodes. The emission and thermal stability are almost identical to that of BAM:Eu2+ while the absorption band is broader and reaches into the near UV range. Therefore, Na3RbMg7(PO4)6:Eu2+ is a promising candidate as a blue emitter in high CRI full conversion LEDs. To investigate the site preference of Eu2+, DFT and Ligand Field Theory based calculations were performed to successfully predict the emission spectrum. An unusual decay behavior was observed at low temperatures and the underlying mechanism involving spin-forbidden transitions of Eu2+ is discussed.

On a blue emitting phosphor Na3RbMg7(PO4)6:Eu2+ showing ultra high thermal stability

f–f Transition intensities of europium(III) acetate complexes in a single crystal and in solution

IR and Raman spectra (100–4000 cm−1) of Eu2(CH3COO)6 · 8H2O have been recorded in the solid state. A model has been proposed, and bands have been assigned on the basis of normal vibration analysis using the NORVIB program. The calculated frequencies are in agreement with the experimental values. We find that the present band assignments are different from the empirical assignments.

Yansheng Yang

Papers

Normal vibration analysis of europium(III) acetate hydrate I — The NORVIB program