Synthesis of Red-Emitting CaAlSiN₃:Eu²⁺Phosphors through a Cost-Effective Synthetic Route

We report a cost-effective synthetic route to prepare red-emitting CaAlSiN3:Eu2+ phosphors for white light-emitting diodes. Pure CaAlSiN3:Eu2+ phosphors can be achieved at 1550°C under NH3 atmosphere from CaC2, CaCO3, Si3N4, AlN and Eu2O3 starting powders, rather than the air-sensitive starting powders. CaC2 is selected as the reduction agent and calcium resource, while the carbon contamination from CaC2 is suppressed by the addition of CaCO3 and the NH3 atmosphere. The obtained CaAlSiN3:Eu2+ phosphors are orange in color and emit strong red light under 450 nm excitation.