Enhanced luminescence and tunable color of Sr8CaSc(PO4)7:Eu2+, Ce3+, Mn2+ phosphor by energy transfer between Ce3+-Eu2+-Mn2

The crystal structure of Sr8CaSc(PO4)7:Eu2+, Ce3+, Mn2+ phosphor was refined and determined from Rietveld refinement method. The occupation for Eu2+, Ce3+ at Ca2+ ion site and Mn2+ at Sc3+ site in Sr8CaSc(PO4)7 host material were proved by the XRDs profiles and Van Uitert equation. The designed tri-energy transfer process of Eu2+→Mn2+, Ce3+→Mn2+ and Ce3+→Eu2+→Mn2+ occurred in Sr8CaSc(PO4)7 phosphor, and furtherly certified by their decay curves. The corresponding calculated energy transfer efficiencies indicated that the energy transfer Ce3+→Mn2+ made the main contribution on the emission enhancement of Mn2+ ion. The chromaticity and color temperature of Sr8CaSc(PO4)7:xEu2+, yCe3+, zMn2+ phosphors were conveniently adjusted in a broad region by the tri-energy transfer and different excitation energy, which is from (0.2914, 0.3396), 7606 K to (0.4458, 0.3303), 2013 K under 311 nm excitation and (0.2248, 0.5466), 8000 K to (0.3978, 0.4932), 4231 K under 370 nm excitation, respectively. Meanwhile, the corresponding quantum efficiency was improved up to 36.3% in Sr8CaSc(PO4)7:1%Eu2+, 2.5%Ce3+, 2%Mn2+ phosphor by tri-energy transfer and high excitation energy 311 nm. The corresponding fabricated 310 SCSPO-LED and 370 SCSPO-LED showed the chromaticity and color temperature as (0.241, 0.345), 10818 K and (0.339, 0.254), 4673 K respectively, that prove Sr8CaSc(PO4)7:xEu2+, yCe3+, zMn2+ phosphors have potential application value on NUV WLEDs. [Display omitted] •The PLQY was improved by tri-energy transfer between Ce3+-Eu2+-Mn2+ ions.•The chromaticity and color temperature were conveniently adjusted in a broad region.•Ce3+→Mn2+ energy transfer made the main contribution on the emission enhancement of Mn2+ ion.