A white-emitting CaY2Al4SiO12: Dy3+ phosphors with excellent optical properties and thermal stability by partially substituting Y3+ with Gd3+.

A series of CaY 1.97−y Al 4 SiO 12 : 0.03Dy3+, yGd3+ white phosphors were prepared by high temperature solid phase method. The structure and phase purity of representative samples were characterized by Rietveld refinement and Fourier transform infrared spectrum. In CaY 1.97 Al 4 SiO 12 : 0.03Dy3+ phosphors, the sample has two characteristic peaks at 485 nm (4F 9/2 →6H 15/2) and 574 nm (4F 9/2 →6H 13/2) excited at 350 nm. In CaY 1.97−y Al 4 SiO 12 : 0.03Dy3+, yGd3+ phosphors, the luminescence intensity of CaY 1.97 Al 4 SiO 12 : 0.03Dy3+ samples were significantly improved by partially substituting Y3+ in the host with Gd3+, showing strong white luminescence. The reasons for enhanced luminescence after partial substitution of Gd3+ are discussed in detail from the perspective of phosphor structure and crystal field effect around Dy3+. In addition, with the substitution of Gd3+, the sample showed low thermal quenching, which was illustrated by combining the calculation of Debye temperature and activation energy. Finally, the chromaticity coordinates of CaY 1.97−y Al 4 SiO 12 : 0.03Dy3+, yGd3+ phosphors were all located in the white region, and combined with the 310 nm chip package, white phosphors with high color rendering index were obtained. Therefore, CaY 1.93 Al 4 SiO 12 : 0.03Dy3+, 0.04Gd3+ phosphors can be used as high-quality materials in the field of w-LED. [ABSTRACT FROM AUTHOR]