The tetravalent manganese activated SrLaMgTaO 6 phosphor for w-LED applications

Abstract We report a new Mg 2+ , Mn 4+ co-doped red-emitting SrLaMgTaO 6 phosphor for solid state lighting. The phosphor can be efficiently excited in the wavelength range of 250–500 nm, which matches well with the emission wavelengths of blue or NUV chips. The photo-luminescence spectra exhibit the highest emission peak at 692 nm from 2 E g → 4 A 2 spin forbidden transition of Mn 4+ under NUV excitation. The Mg 2+ co-dopant for charge compensation plays a key role in enhancing the luminescence intensity by a factor of 2.8. The incorporation of Mg 2+ ion in the host could not only suppress the energy migration among Mn 4+ ions but also eliminates the charge imbalance in Mn 4+ − Mg 2+ pairs. W-LED fabrication with different mass ratios of yellow emitting YAG: Ce 3+ and red emitting SrLaMgTaO 6 :Mn 4+ /Mg 2+ phosphors is designed to explore its possible application in warm w-LEDs with high CRI. The w-LEDs fabricated with the integration of SrLaMgTaO 6 :Mn 4+ /Mg 2+ red phosphor show changing trends toward warm white light with lower color temperature and higher CRI than that based on single yellow emitting YAG:Ce 3+ phosphors. The results suggest that SrLaMgTaO 6 : Mn 4+ /Mg 2+ phosphor has great potential for the warm w-LEDs application as a suitable red light component.