Synthesis and luminescence properties of Dy3+-doped Mg2InSbO6 yellow-emitting phosphors with abnormal thermal quenching performance for w-LEDs

A series of novel yellow-emitting antimonate-based Mg₂InSbO₆:xDy³⁺ (x = 0.5, 1, 2, 10, 15, and 25 mol%) phosphors was firstly synthesized by a solid-state reaction. The crystal structure, X-ray diffraction (XRD), photoluminescence (PL) properties, and the thermal quenching behaviours of prepared Mg₂InSbO₆:Dy³⁺ samples were exhaustively studied. The Mg₂InSbO₆ lattice has a trigonal crystal system, which possesses the R \(\overline{3 }\) (#148) space group. The as-prepared Mg₂InSbO₆:Dy³⁺ phosphors show a bright yellow emission peak at 572 nm under near-ultraviolet (n-UV) 349 nm excitation, which is attributed to the ⁴F_9/2–⁶H_13/2 transition of Dy³⁺. The optimum product is Mg₂InSbO₆:10 mol% Dy³⁺ with the estimated R_c = 13.05 Å. The optimum sample Mg₂InSbO₆:10 mol% Dy³⁺ exhibits abnormal thermal quenching phenomenon. The emission intensity reaches a maximum at 420 K. The fluorescence lifetime of Mg₂InSbO₆:10 mol% Dy³⁺ phosphor is measured to be 0.416 ms. Besides, the CIE chromaticity coordinates of Mg₂InSbO₆:xDy³⁺ (x = 0.5–25 mol%) phosphors change slightly, which possess low correlated color temperature (CCT) and high color purity. All findings suggest that Mg₂InSbO₆:Dy³⁺ samples can serve as white emission candidates for white light-emitting diodes (w-LEDs).