Synthesis and characterization of Mn-activated lithium aluminate red phosphors

► Mn-doped α-LiAlO2 single phase powders were successfully synthesized by the sol-gel method. ► Mn4+ in the host α-LiAlO2 matrix could be identified by the ESR spectroscopic analysis. ► PL red emission peaks derived from d-d transitions of the Mn4+ were observed around 670 nm. ► Mn4+ could be an activator only for the host matrix with low temperature phase of α-LiAlO2. ► Highest emission intensity was achieved at the Mn-doping of 0.10 mol/%.