Preparation, crystal structure and luminescence properties of red-emitting Lu3Al5O12: Mn4+ ceramic phosphor

Abstract

A series of red-emitting Mn4+ doped Lu3Al5O12 (LuAG) ceramic phosphors were successfully prepared by a simple solid-state reaction method in a high-temperature muffle. MgO was co-doped as sintering aids and Mg2+ ions helped to realize the charge balance. The relations between the luminescence properties, crystal structures and the microstructures were well established. Results indicated that MgO promoted the densification of the ceramics as the specimens’ relative densities were up to 99%. Moreover, the substitution of Al3+ with Mg2+ have changed crystal structures and further affected the luminescent properties. Overall, the obtained ceramic phosphors showed strong red-light emission under excitation of ultraviolet and blue light. By optimizing the Mg2+ and Mn4+ concentration, a quantum efficiency (QE) as high as 47.8% can be achieved under the excitation of 460 nm light, indicating that the LuAG: Mn4+ ceramic phosphors are promising candidates for WLEDs applications.