Characterization in activators' distribution and photoluminescence properties of Ce3+ doped MgAlON transparent fluorescent ceramic

A novel Ce3+ doped MgAlON transparent ceramic with high transparency in UV-VIS-NIR regions was fabricated by pressureless sintering. The highly dense transparent ceramic was colorless in sight. Under the excitation of the UV light, the fluorescent ceramic emitted a blue light with spectrum centered at 420 nm, which was caused by the 5d-4f energy transition of Ce3+. The fluorescent ceramic exhibited slight thermal quenching at 200 °C with 77% of the intensity at room temperature. The result of fluorescent lifetime measurement indicated there existed two emission centers in the sample. By combining with the cathodoluminescence (CL) mapping method, the Ce3+ ions were demonstrated to be in two regions: a. most of them existed in the expanding regions of grain boundaries; b. the residual ones were located in the lattices of the host grains.