Emission tunable of Mg0.695Si0.695Al1.39O3.65N0.35:Eu2+,Mn2+ oxynitride phosphors via energy transfer for WLEDs

A series of Eu2+ doped and Eu2+/Mn2+ co-doped Mg0.695Si0.695Al1.39O3.65N0.35 (MSAON) phosphors were synthesized by solid-state reaction at a lower temperature of 1500 degrees C. The crystal morphology and structure of MSAON host were characterized by SEM, TEM and XRD. The quantum yield (QY) for Eu2+ doped MSAON phosphors was measured as high as 62%, indicating the excellent luminous efficiency. For the Eu2+/Mn2+ co-doped MSAON phosphor, the photoluminescence spectrum and delay curves reveal the efficient energy transfer (ET) process from Eu2+ to Mn2+ ions. Meanwhile, the corresponding energy transfer efficiency, critical distance and mechanism are discussed in detail. Temperature-dependent emission spectrum shows the thermal and color stabilities. The emission color of MSAON:Eu2+,Mn2+ phosphors could be tuned from blue through white to red via varying the concentration of Mn2+ ions. White-light-emitting diodes (WLEDs) were successfully fabricated by encapsulating the phosphors in n-UV LED (365 nm) devices obtaining white light with color rendering index (CRI) as high as 87.7. The results reveal that the MSAON:Eu2+,Mn2+ phosphors could have potential application in the field of n-UV WLEDs. (C) 2020 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

A series of Eu2+ doped and Eu2+/Mn2+ co-doped MSAON phosphors were synthesized at 1500 degrees C, showing high quantum yield and efficient energy transfer process. The emission color could be tuned from blue to red by adjusting the concentration of Mn2+ ions, with potential application in n-UV WLEDs.