Abstract: To improve the luminescence property of blue-green phosphors, the conventional high-temperature solid-phase method was used to synthesize LaNbO₄∶Dy³⁺ and LaNbO₄∶Dy³⁺,Ca²⁺ phosphors in this paper. The XRD, fluorescence spectra and CIE chromaticity coordinates of the samples were tested to investigate the effects of Dy³⁺ doping and Dy³⁺,Ca²⁺ co-doping on the performance of niobate phosphors. The results show that the diffraction peaks of LaNbO₄∶Dy³⁺ as well as LaNbO₄∶Dy³⁺,Ca²⁺ phosphors all match the diffraction peaks of standard card. The excitation spectra of the samples are composed of two broadband excitation peaks and a series of sharp excitation peaks, the strongest excitation peaks of LaNbO₄∶Dy³⁺ and LaNbO₄∶Dy³⁺,Ca²⁺ are 387 and 472 nm, respectively. Under excitation at a wavelength of 387 nm, the strongest emission peaks of the sample are 575 and 477 nm, respectively. The best luminescence intensity is obtained when the concentration of Dy³⁺doping is 0.05. When Dy³⁺ and Ca²⁺ are co-doped, the sample has the best luminescence property when the concentration of Ca²⁺ is 0.05. Through the color card coordinates, it can be observed that LaNbO₄∶Dy³⁺,Ca²⁺ is more concentrated in the blue-green region than LaNbO₄∶Dy³⁺,which shows that Dy³⁺ and Ca²⁺ co-doped LaNbO₄ have better luminescence effect, and the co-doped samples show more stable luminescence property, indicating that the phosphor is a more stable blue-green phosphor that can be excited by UV light.

Key words: phosphor, rare earth niobate, high temperature solid state method, luminescence property, co-doping, blue-green light