Enhanced yellow emission from SrGa₂B₂O₇: Dy³⁺, Si⁴⁺/ Al³⁺ and accurate white emission from the single-composition of SrGa₂B₂O₇: Dy³⁺, Si⁴⁺, Bi³⁺

Dy³⁺ exhibits yellow emission with a narrow half-width and higher chemical stability than Ce³⁺. But the emission intensity of Dy³⁺ is generally quite weak, limiting the application of Dy³⁺ in fluorescence. In this study, yellow phosphors of SrGa₂B₂O₇ doped with Dy³⁺ were synthesized and characterized. Co-doping with Si⁴⁺ or Al³⁺ significantly enhances the emission intensity of Dy³⁺. The quantum yield of Sr_0.95Ga_1.60B₂O₇: 0.05Dy³⁺, 0.40Si⁴⁺ is 33.3%, which represents a very high value for Dy³⁺ based phosphors. These yellow phosphors can be combined with blue-violet LED to obtain a white LED. Moreover, a single-component white phosphor was obtained by co-doping with Dy³⁺, Si⁴⁺ and Bi³⁺. Accurate tuning of colors from cool white to warm white was achieved by adjusting the ratio of Si⁴⁺, and color coordinate of (0.333, 0.333) corresponding to standard white light was obtained. The yellow and white phosphors both have high thermal stability. The intensity of the yellow phosphors at 473 K is 87.4% of the intensity at room temperature, and the intensity of the white phosphors at 473 K maintain 96.9% of the intensity at room temperature. The significant improvement of quantum yield achieved in SrGa₂B₂O₇: Dy³⁺, Si⁴⁺ and highly accurate white emission from SrGa₂B₂O₇: Dy³⁺, Si⁴⁺, Bi³⁺ demonstrate the high potential of Dy for application in phosphors.