Red emission generation in Ce3+/Mn2+ co-doping Y3Al5O12 phosphor ceramics for warm white lighting emitting diodes

Abstract Y 3 Al 5 O 12 :Ce 3+ /Mn 2+ /Si 4+ phosphor ceramics were fabricated by solid state reaction. Red emission is obtained, which is attributed to the Mn 2+ : 4 T 1 → 6 A 1 spin-forbidden transition under the excitation of 450 nm via the efficient energy transfer from Ce 3+ to Mn 2+ .The green emission (535 nm) originating from Ce 3+ and the orange emission (587 nm) from Mn 2+ ions were observed. Mn 2+ ions are more inclined to occupy Al 3+ octahedral sites and the Si 4+ ions locate in the Al 3+ tetrahedral sites and their co-doping is for charge compensation. The red emission component in Ce 3+ /Mn 2+ /Si 4+ doping YAG phosphor ceramics is significant for obtaining warm white lighting upon increasing Mn 2+ concentration under 450 nm excitation. White light emitting diodes were successfully constructed by combining the fabricated ceramics with the GaN blue chips.