基于双发光位点能量传递构建高效窄带钙钛矿构型K2BaPO4F:Eu2+荧光粉OACSTPCD

Along with the development of versatile trichromatic phosphors,exploring novel narrow-band blue-emit-ting phosphors has been an ongoing focus in liquid crystal display backlighting to satisfy the high-quality display de-mands.Herein,an intriguing narrow-band blue-emitting phosphor K2BaPO4F:Eu2+belonging to the perovskite-type structural prototype is synthesized via the solid-state reaction.Structural analysis indicates that the[FK4Ba2]octahe-dra is interlinked with each other by sharing Ba and K atoms to build a three-dimensional network together with[PO4]tetrahedra in the cavities.Rietveld refinement analysis shows that the Eu2+ions reside in both Ba2+and K+sites to form the[Eu(1)O8F2]and[Eu(2)O6F2]polyhedra,which totally induce an intense blue emission peaking at 432 nm with a narrow full width at half-maximum of 43 nm,theoretically verified by the dipole-dipole interaction in the Eu(1)→Eu(2)energy transfer process.The electronic structure of K2BaPO4F matrix is studied by the first-prin-ciple calculation on the basis of the density functional theory,demonstrating that it has a large indirect band of 5.035 eV.The K2BaPO4F:Eu2+phosphor exhibits a suitable thermal stability(I493 K/I293 K=64％)and possesses the satisfac-tory internal/external quantum efficiency of 72.8％/46.4％,which although is inferior to that of the representative BaMgAl10O17:Eu2+,K1.6Al11O17+δ:Eu2+and Na3Sc2(PO4)3:Eu2+phosphors,yet surpasses some other recently reported blue-emitting phosphors.Consequently,the present work not only demonstrates the potential of K2BaPO4F:Eu2+phosphor as a new narrow-band blue-emitting phosphor candidate,but provides the possibility for exploring the novel phosphors inspired by the mineral-type structural prototypes.