(M,Ca)AlSiN3:Eu2+ (M=Sr, Mg) long persistent phosphors prepared by combustion synthesis and applications in displays and optical information storage

Eu 2+ -doped CaAlSiN 3 ‐type structure nitrides have been extensively studied as a red-emitting phosphors in white light emitting diodes (w-LEDs), but there are few reports of systematic research on the effect of solid solution substitution on their long persistent luminescent properties. In this work, a series of (M,Ca)AlSiN 3 :Eu 2+ (M = Sr, Mg) phosphors have been successfully synthesized by efficient combustion synthesis . We investigated the effect of Sr and Mg solid solution on long persistent luminescent properties. Thermoluminescence (TL) measurements were performed in those persistent phosphors to obtain direct experimental results on the trap depth. The results show that the SrAlSiN 3 :0.2 at% Eu 2+ phosphor exhibits the most intense red persistent luminescence with the persistent time of as long as 200 min at the threshold value of 0.32 mcd/m 2 due to the presence of more trap levels with suitable depths of 0.71 eV. Compared with the solid solution of Sr, the solid solution of Mg ions can increase the depth of trap levels in CaAlSiN 3 . Among them, Mg 0.2 Ca 0.8 AlSiN 3 :0.2 at% Eu 2+ phosphor achieved a maximum trap depth of 0.98 eV, making it a promising candidate for optical information storage applications.