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

A series of CaY1.97−yAl4SiO12: 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 CaY1.97Al4SiO12: 0.03Dy3+ phosphors, the sample has two characteristic peaks at 485 nm (4F9/2→6H15/2) and 574 nm (4F9/2→6H13/2) excited at 350 nm. In CaY1.97−yAl4SiO12: 0.03Dy3+, yGd3+ phosphors, the luminescence intensity of CaY1.97Al4SiO12: 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 CaY1.97−yAl4SiO12: 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, CaY1.93Al4SiO12: 0.03Dy3+, 0.04Gd3+ phosphors can be used as high-quality materials in the field of w-LED.