Atmospheric pressure preparation of red-emitting CaAlSiN3:Eu2+ phosphors with variable fluxes and their photoluminescence properties

A red-emitting Eu 2+ activated CaAlSiN 3 phosphor was successfully prepared via an atmospheric pressure solid-state reaction method with the aid of variable fluxes, namely SrF 2 , NH 4 F, BaF 2 , NaF, AlF 3 , CaF 2 and NH 4 Cl. The experimental results showed that the addition of SrF 2 flux effectively reduced the formation temperature of CaAlSiN 3 : Eu 2+ about 100   °C, improved the morphology of CaAlSiN 3 : Eu 2+ and suppressed the appearance of AlN impurity phase, suggesting that SrF 2 flux modifies the formation mechanism of CaAlSiN 3 : Eu 2+ . The phosphor of the CaAlSiN 3 :Eu 2+ produced with 4   wt% SrF 2 flux had an enhanced emission intensity, which was a result of the high crystallinity , the absence of AlN secondary phases, and the clean surfaces of the particles in the final product.