Cyan-emitting Ca9NaGd2/3(PO4)7∶Eu2+ phosphors were synthesized via high temperature solid-state route.X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) were used to verify the phase and morphology of the Ca9NaGd2/3(PO4)7∶Eu2+ (CNGP∶Eu2+) phosphors.The as-obtained phosphor exhibits a broad excitation band of 250-420 nm,which is near the ultraviolet region.An intense asymmetric cyan emission at 496 nm corresponds to the 5d-4f transition of Eu2+.The multiple-site luminescent properties of Eu2+ ions in CNGP benefit from versatile structure of β-Ca3(PO4)2 com-pounds.The effective energy transfer distance is 5.46 nm (through the spectral overlap calculation),validating that the resonant energy migration type is via dipole-dipole interaction mechanism.Compared to the initial one at room temperature,the luminescent intensity of CNGP∶Eu2+ phosphor can maintain 77％ as it is heated up to 420 K.A white light-emitting diode (WLED) with excellent luminescent properties was successfully fabricated.Moreover,the CIE chromaticity coordinates of fabricated WLED driven by changing current just change slightly.

Shihua Liu;Bin Deng;Junhui Yang;Jinhua Liu;Jun Chen;Fanhua Zeng;Huanyou Wang;Ruijin Yu;Gongguo Zhang

College of Chemistry & Pharmacy,Northwest A&F University,Yangling 712100,China;College of Chemistry & Biology and Environmental Engineering,Xiangnan University,Chenzhou 423043,China;Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds Research and Application,Chenzhou 423043,China;Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials,College of Materials and Chemical Engineering,China Three Gorges University,Yichang 443002,China;Department of Chemistry and Chemical Engineering,Jining University,Qufu 273155,China

稀土学报（英文版）

[1]Shihua Liu;Bin Deng;Junhui Yang;Jinhua Liu;Jun Chen;Fanhua Zeng;Huanyou Wang;Ruijin Yu;Gongguo Zhang-.Multi-site occupancies and luminescence properties of cyan-emitting Ca9-xNaGd2/3(PO4)7∶Eu2+ phosphors for white light-emitting diodes)[J].稀土学报（英文版）,2022(02):243-252

occupancies,xNaGd2,Cyan,Ca9NaGd2,CNGP

Multi,site,luminescence,properties,cyan,emitting,PO4,Eu2+,phosphors,white,diodes,were,synthesized,via,high,temperature,solid,state,route,ray,powder,diffraction,scanning,electron,microscopy,used,verify,phase,morphology,obtained,exhibits,broad,excitation,band,which,near,ultraviolet,region,An,intense,asymmetric,emission,corresponds,5d,4f,transition,multiple,luminescent,ions,benefit,from,versatile,structure,Ca3,com,pounds,effective,energy,transfer,distance,through,spectral,overlap,calculation,validating,that,resonant,migration,type,dipole,interaction,mechanism,Compared,initial,one,room,intensity,maintain,heated,WLED,excellent,was,successfully,fabricated,Moreover,CIE,chromaticity,coordinates,driven,by,changing,current,just,change,slightly

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