Mn2+ activated MgAlON transparent ceramic: A new green-emitting transparent ceramic phosphor for high-power white LED

A novel Mn2+ activated green-emitting MgAlON transparent ceramic phosphor was synthesized from Mg0.21Al2.57O3.80N0.20:0.03Mn2+ (MgAlON:Mn) phosphor powder by pressureless sintering combining with hot isostatic pressing. By crystalline structure refinement and cathodoluminescence (CL) characterization, it is demonstrated that Mn2+ was dissolved in the spinel lattice and occupied the tetrahedral site. The ceramic, retaining high transmittance in UV-vis region (up to 82% at 800 nm) and excellent thermal-mechanical properties of MgAlON transparent ceramic-matrix, shows a strong green emission at 513 nm under 445 nm light excitation. Compared with its powder counterpart, the ceramic phosphor exhibits higher green color purity, higher internal quantum efficiency (47%) and lower thermal quenching. It is suggested that this novel green solid phosphor could be applied in high color rendering and high-power white light-emitting diodes when combined with a red solid phosphor and a blue LED chip.