A narrow-band blue emitting phosphor Ca 8 Mg 7 Si 9 N 22 :Eu 2+ for pc-LEDs

Ca 8 Mg 7 Si 9 N 22 crystallizes in a tetragonal space group P 4 2 / nmc (No. 137) with a unit cell of a = 7.3271(11) Å and c = 10.336(2) Å. Ca 8 Mg 7 Si 9 N 22 :Eu 2+ shows a narrow-band blue emission peaking at 400 nm with an intriguing bandwidth ∼34 nm and shows remarkably high thermal quenching resistance, maintaining 92% photoluminescence emission intensity at 420 K and 75% at 700 K of that measured at room temperature.