Preparation of high performance CaAlSiN3:Eu2+ phosphors with the aid of BaF2 flux

A strong red-emitting Eu2+ activated CaAlSiN3 phosphor was successfully prepared by a pressureless low temperature solid-state reaction method with the aid of fluxes, namely BaF2, CaF2, NH4F, and H3BO3. The experimental results showed that the addition of BaF2 flux effectively reduced the temperature of formation of CaAlSiN3:Eu2+ by about 100 K and suppressed the volatilization of the raw materials, suggesting that BaF2 flux modifies the mechanism of formation of CaAlSiN3:Eu2+. The powder of the CaAlSiN3:Eu2+ phosphor produced with 6 wt% BaF2 flux had an enhanced emission intensity, which was a result of the high crystallinity, the absence of secondary phases, the narrow particle-size distribution, and the clean surfaces of the particles in the final product.