Zhi-wei Zhang

Enhanced novel orange red emission in LiSr4−x(BO3)3:xSm3+ by K+

LiSr4−x(BO3)3:xSm3+ and LiSr3.985−x(BO3)3:0.015Sm3+, xK+ phosphors were prepared by solid-state reactions. The phases and luminescent properties of the obtained phosphors were characterized. The results demonstrate that the phosphors particles emit an intensive reddish orange light emission under excitation at 403xa0nm. LiSr4−x(BO3)3:xSm3+ phosphor can be efficiently excited by ultraviolet and blue light, and the emission spectrum consists of three emission peaks at 564, 601 and 647xa0nm. The introduction of the charge compensator K+ into the LiSr4−x(BO3)3:xSm3+ phosphor matrix promotes the increase of the emission intensity, as well as the decrease of the Eg value. Results suggest that LiSr3.97(BO3)3:0.015Sm3+, 0.015xa0K+ is a promising orange–red emitting phosphor for UV LED applications.

Synthesis and luminescence of Eu3+-doped in triple phosphate Ca8MgBi(PO4)7 with whitlockite structure

Triple whitlockite-type structure-based red phosphors Ca8 MgBi1-x(PO4)7:xEu(3+) (x = 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80 and 1.00) were synthesized by a conventional solid-state reaction route and characterized by their X-ray crystal structures. The X-ray diffraction (XRD) patterns, Fourier transform infrared spectra, morphologies, photoluminescence spectra, UV/Vis reflectance spectra, decay times and the International Commission on Illumination (CIE) chromaticity coordinates of Ca8MgBi1-x(PO4)7:xEu(3+) were analyzed. Eu-doped Ca8MgBi(PO4)7 phosphors exhibited strong red luminescence with peaks at 616 nm due to the (5)D0 → (7)F2 electric dipole transition of Eu(3+) ions after excitation at 396 nm. The UV/Vis spectra indicated that the band gap of Ca8MgBi0.30(PO4)7:0.70Eu(3+) is larger than that of Ca8MgBi(PO4)7. The phosphor developed in this study has great potential as a red-light-emitting phosphor for UV light-emitting diodes.