CaMg₂Al₁₆O₂₇:Mn⁴⁺-based Red Phosphor: A Potential Color Converter for High-Powered Warm W-LED

Abstract

New non-rare-earth-based oxide red phosphor discovery is of great interest in the field of energy-efficient LED lighting. In this work, a novel blue-light activated CaMg2Al16O27:Mn(4+) (CMA:Mn(4+)) phosphor, showing strong red emission peaked at ∼655 nm under 468 nm excitation, is prepared by a solid-state reaction route. The microstructure and luminescent performance of this red-emitting phosphor are investigated in detail with the aids of X-ray diffraction refinement, diffuse reflection spectra, steady-state photoluminescence spectra and temperature-dependent PL/decay measurements. The crystal field strength (Dq) and the Racah parameters (B and C) are carefully calculated to evaluate the nephelauxetic effect of Mn(4+) suffering from the CMA host. After incorporating CMA:Mn(4+) and YAG:Ce(3+) phosphor microcrystals into the glass host via a "phosphor-in-glass (PiG)" approach, warm white-light is achieved in the assembled high-powered w-LED device, thanks to the improved correlated color temperature and color rendering index.