Luminescence properties of CaAlSiN3:Eu2+ phosphor prepared by direct-nitriding method using fine metal hydride powders

Abstract Nitride phosphor, CaAlSiN 3 :Eu 2+ , was efficiently synthesized without any impurity phase by the direct-nitriding method using metal hydride fine powders of (Ca 0.97 Eu 0.03 )AlSiH x and/or CaH 2 in a particle size range below 20 μm as starting materials under atmospheric pressure heating conditions in a stream of N 2 gas. High-quality powders of CaAlSiN 3 :Eu 2+ (3 at%) phosphor were obtained from such metal hydride powder mixed with a large excess amount of CaH 2 powder (>30 wt%) as a flux and gave an intense red emission band peaking at 650 nm under the excitation of 450 nm, of which the relative integrated emission intensity was about 110% versus that of a commercially-available YAG:Ce 3+ (P46-Y3) standard phosphor. Also, the thermal quenching effect was as low as the CaAlSiN 3 :Eu 2+ phosphors prepared by the other methods (−6% at 150 °C), so that this direct-nitriding method was noted as one of excellent procedures to produce the high-quality nitride phosphors for white-LED illumination lamps.