Translucent red-emitting AlN: Mn phosphor ceramics with high luminescence thermal stability

Developing new phosphor ceramics with higher thermal conductivity is a matter of priority for high power solid-state lighting. Herein, translucent red-emitting AlN : Mn phosphor ceramic with high thermal conductivity (72.37 W m −1  K −1 at 25 °C) and high luminescence thermal stability are successfully fabricated by pressureless sintering at 1800 °C for 3 h. Preparation process, photoluminescence , afterglow and electronic compensation mechanisms were discussed in detail. TEM analysis showed that the tiny grain boundaries are composed of disordered Al 2 O 3 phases. The EPR and TL spectra were used to reveal the O-related trap distribution. The AlN: Mn phosphor ceramics have brightly red afterglow with the longest afterglow time of 88 s and possess high luminescence thermal stability, that is to say, the luminescence intensity at 250 °C preserves 93.7% of that at room temperature . The encapsulated AlN: Mn LED device has a very bright red emission peak at 598 nm with a color purity of about 99%, indicating great application potential in solid-state lighting.