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Novel yellow-emitting phosphors of Dy3+-doped double perovskite Ca2MgTeO6 were synthesized by using a conventional high-temperature solid-state reaction.The phase purity,particle morphology,size distribution,elemental composition,luminescence properties,and luminescence decay curves of the resulting products were then analyzed in detail.The Ca2MgTeO6∶Dy3+,Na+ phosphors show three emission peaks after near-ultraviolet excitation at 350 nm,which correspond to 4F9/2 → 6H11/2,4F9/2→ 6H13/2,and 4F9/2 → 6H13/2 transitions,respectively.Among them,the strongest peak is observed at 573 nm.The best doping content of Dy3+ in Ca2MgTeO6∶xDy3+,xNa+ phosphors is x =5 mol％.The calculated critical distance of energy transfer between Dy3+ ions is 1.6 nm.Luminescence quenching is confirmed to be due to dipole-dipole interactions among Dy3+ ions.The phosphors show excellent thermal stability with high activation energy (0.27 eV).The Commission Intemationale de l'Eclairage(CIE) chromaticity coordinates of the Ca2MgTeO6Dy3+,Na+ phosphors are located in the yellow region.White light-emitting diodes (w-LEDs) were fabricated with a high color rendering index (Ra) of 88 and a good correlated color temperature (CCT) of 5440 K.All observed properties indicate that Ca2MgTeO6∶Dy3+,Na+ phosphors have potential applications in display and photonic devices.