Structure and luminescence properties of Ce3+ doped KBa1−x(Mg/Zn)xY(BO3)2 and K1−yNayBaY(BO3)2 phosphors evolved from cation substitution

Publication date: 1 August 2017
Source:Optics & Laser Technology, Volume 93
Author(s): Rui Xu, Yujun Liang, Shiqi Liu, Yingli Zhu, Xingya Wu, Kai Li, Wei Zhou
The tunable blue-emitting KBa1−x(Mg/Zn)xY0.95(BO3)2:0.05Ce³⁺ and K1−yNayBaY0.95(BO3)2:0.05Ce³⁺ phosphors have been investigated via cation substitution of Mg²⁺/Zn²⁺ for Ba²⁺ and Na⁺ for K⁺ in KBaY(BO3)2 host. The crystal structures, photoluminescence properties, thermal stability and the effect of Mg²⁺/Zn²⁺/Na⁺ concentration on the luminescence characteristics were investigated in detail. The XRD analysis implied that KBa1−x(Mg/Zn)xY(BO3)2 solid solutions were limited, while continuous solid solution was possible in K1−yNayBaY(BO3)2 system. Upon the excitation at 365nm, the emission peaks of KBa1−x(Mg/Zn)xY0.95(BO3)2:0.05Ce³⁺ (0⩽x⩽0.6) blue-shifted from 435 to 424nm, and K1−yNayBaY0.95(BO3)2:0.05Ce³⁺ (0⩽y⩽1) blue-shifted from 435 to 427nm with the Mg²⁺/Zn²⁺/Na⁺ doping concentration increase. The thermal stabilities of KBa1−x(Mg/Zn)xY0.95(BO3)2:0.05Ce³⁺ phosphors were enhanced from 20°C to 200°C by increasing the concentration of Mg²⁺ and Zn²⁺. The substitution of Na⁺ for K⁺ led to a decrease in the proportion of ⁵D-²F5/2 and ⁵D-²F7/2 corresponding to the Gaussian fitting of Ce³⁺ in K1−yNayBaY0.95(BO3)2:0.05Ce³⁺ phosphors. At the temperature increased, the full width at half maximum of photoluminescence band of K0.8Na0.2BaY0.95(BO3)2:0.05Ce³⁺ decreased. However, the decreasing trend of FWHM became less obvious with the increasing concentration of Na⁺ in the temperature dependent photoluminescence spectra of K1−yNayBaY0.95(BO3)2:0.05Ce³⁺ phosphors.



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