Improvement of luminescence performance of single-phase white-emitting Na3Gd(PO4)2:Dy3+ phosphor by co-doping with Eu3+.

Na 3 Gd(PO 4) 2 : Dy3+, Eu3+ phosphors were obtained by the co-doping of Dy3+ and Eu3+, and the red light emitted by Eu3+ solved the issue of high CCT due to the lack of a red-light band in the emission spectra of Dy3+. The CIE coordinate of the Dy3+and Eu3+co-doped Na 3 Gd(PO 4) 2 phosphors is calculated as (0.3442, 0.3320), which is located in the white region. The excellent thermal stability further indicated that the phosphors have great potential for applications in UV/NUV excited w-LEDs. [Display omitted] In this study, novel Na 3 Gd(PO 4) 2 :Dy3+, Eu3+ phosphors were synthesized by a high-temperature solid-state method. Single-phase white lighting-emitting Na 3 Gd(PO 4) 2 :Dy3+ phosphors exhibited blue and yellow emissions under 350 nm excitation, respectively. Eu3+-doped phosphors exhibited strong red emission at 621 nm under 394 nm excitation. Compared with that of Na 3 Gd(PO 4) 2 :Dy3+, the color rendering index of Na 3 Gd(PO 4) 2 :Dy3+, Eu3+ phosphor is improved from 74.7 to 78.9. Moreover, the correlated color temperature of Na 3 Gd(PO 4) 2 :Dy3+, Eu3+ reduced significantly from 9872 K to 5460 K. The maximum energy transfer from Dy3+ to Eu3+ in Na 3 Gd(PO 4) 2 :Dy3+, Eu3+ phosphor was ∼ 76.2% at Eu3+ concentration of 0.1. The chromaticity coordinate of the Dy3+ and Eu3+co-doped Na 3 Gd(PO 4) 2 phosphor was calculated as (0.3442, 0.3320), which is located in the white region. Furthermore, temperature-dependent photoluminescence emission properties indicate that the prepared phosphors exhibit good thermal stability. The study results indicate that the Na 3 Gd(PO 4) 2 :Dy3+, Eu3+ phosphors exhibit immense potential for ultraviolet/near-ultraviolet light-excited white light emitting diodes applications. [ABSTRACT FROM AUTHOR]