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

Y3Al5O12:Ce3+/Mn2+/Si4+ phosphor ceramics were fabricated by solid state reaction. Red emission is obtained, which is attributed to the Mn2+:4T1→6A1 spin-forbidden transition under the excitation of 450 nm via the efficient energy transfer from Ce3+ to Mn2+.The green emission (535 nm) originating from Ce3+ and the orange emission (587 nm) from Mn2+ ions were observed. Mn2+ ions are more inclined to occupy Al3+ octahedral sites and the Si4+ ions locate in the Al3+ tetrahedral sites and their co-doping is for charge compensation. The red emission component in Ce3+/Mn2+/Si4+ doping YAG phosphor ceramics is significant for obtaining warm white lighting upon increasing Mn2+ concentration under 450 nm excitation. White light emitting diodes were successfully constructed by combining the fabricated ceramics with the GaN blue chips.