Currently, the major commercial white light‐emitting diode (WLED) is the phosphor‐converted LED made of the InGaN blue‐emitting chip and the Ce3+:Y3Al5O12 (Ce:YAG) yellow phosphor dispersed in organic epoxy resin or silicone. However, the organic binder in high‐power WLED may age easily and turn yellow due to the accumulated heat emitted from the chip, which adversely affects the WLED properties such as luminous efficacy and color coordination, and therefore reduces its long‐term reliability as well as lifetime. Herein, an innovative luminescent material: transparent Ce:YAG phosphor‐in‐glass (PiG) inorganic color converter, is developed to replace the conventional resin/silicone‐based phosphor converter for the construction of high‐power WLED. The PiG‐based WLED exhibits not only excellent heat‐resistance and humidity‐resistance characteristics, but also superior optical performances with a luminous efficacy of 124 lm/W, a correlated color temperature of 6674 K and a color rendering index of 70. This easy fabrication, low‐cost and long‐lifetime WLED is expected to be a new‐generation indoor/outdoor high‐power lighting source.

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.