A novel thermally stable eulytite-type NaBaBi2(PO4)3:Eu3+ red-emitting phosphor for pc-WLEDs

A new eulytite-type NaBaBi2(PO4)(3):xEu(3+) (NBBP:xEu(3+)) phosphors were synthesized via high temperature solid state reaction. The phase, composition, morphology, band structure, luminescence, electrical properties and thermal stability of the as-prepared NBBP:xEu(3+) samples with various Eu3+ doping content were investigated in detail. XRD, structural refinement results show that the Eu3+ ions replace the Bi3+-site in the lattice. The morphology, elemental composition and molecular structure of the phosphor were studied by SEM, XPS and FT-IR. The band gap of the NaBaBi2(PO4)(3) host obtained by diffuse reflectance spectroscopy is about 4.08 eV, and the Eu3+ ions doping has little effect on the band gap. Room temperature fluorescence spectra show that both near ultraviolet and blue light sources are the excitation pump sources of phosphors, and the electric dipole transition (D-5(0)-> F-7(2)) at 611 nm dominates the red emission. With the increase of doping content, the fluorescence lifetime almost remains unchanged, and the CIE coordinates move to the red region, and the color purity also increases. When the temperature rises to 423 K, the emission intensity of the phosphor remains at 80% of the original intensity at room temperature, and the activation energy Delta E is calculated to be 0.175 eV, indicating that the phosphor has excellent thermal stability. It can be predicted that NBBP:Eu3+ phosphor has potential application in phosphor conversion white light-emitting diodes (pc-WLEDs). (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A novel NBBP:xEu(3+) phosphor was synthesized and investigated for its composition, morphology, luminescence, thermal stability, etc., showing potential application in phosphor conversion white light-emitting diodes.