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

Abstract

Abstract 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 Sr0.95Ga1.60B2O7: 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.