Synthesis and photoluminescence of Mn-Mg co-doped AlON phosphors

A set of spinel-type Al₂₃O₂₇N₅ phosphors co-doped with Mn-Mg were successfully synthesized by solid-state reaction. The results clearly show that the calcination conditions and doping concentration influence the preparation and photoluminescence properties of Mn-doped AlON phosphors. The temperature for obtaining undoped pure phase Al₂₃O₂₇N₅ sample is 1900°C for, while is 1800°C for 10% Mn and 10% Mg(mole fraction) co-doped samples. The lattice parameter increases with Mn concentration, which suggesting Mn²⁺ ion doped into AlON crystal lattice. The PL spectra reveal that there exist a broad-band emission from 350 to 600 nm for undoped and all of doped samples. The broad band green emission is observed in 10% Mn and 10%Mg(mole fraction) co-doped sample. The green emission is attributed to the transition of 3d electrons of Mn²⁺ ion and the blue emission might be related to impurities or Al vacancy.