Eu²⁺-activated MgAl₂Si₄O₆N₄: a novel oxonitridoalumosilicate blue phosphor for white LEDs

Recently, blue-emitting phosphors have attracted great interest due to their application in full-spectrum white light illumination. In this paper, a novel blue-emitting MgAl₂Si₄O₆N₄:Eu²⁺ phosphor was successfully synthesized through the solid-state reaction method in a reducing atmosphere. Under the excitation of near-ultraviolet (n-UV) light, the MgAl₂Si₄O₆N₄:0.02Eu²⁺ phosphor effectively emits a broad blue emission band centered at 456 nm with the FWHM as large as 81 nm. With the increasing Eu²⁺ concentration, the emission bands of MgAl₂Si₄O₆N₄:Eu²⁺ shift to a shorter wavelength and the FWHMs broaden gradually. Moreover, the MgAl₂Si₄O₆N₄:0.02Eu²⁺ phosphor exhibits a slight thermal quenching at a higher temperature. After fabricating the as-prepared MgAl₂Si₄O₆N₄:0.02Eu²⁺ phosphor into a white LED device, the intense neutral white light emission is obtained with excellent CRI (87.4) and CCT (5645 K). These results suggest that the blue MgAl₂Si₄O₆N₄:Eu²⁺ phosphor is a promising candidate in n-UV excited white LEDs.