Synthesis and photoluminescence properties of novel thermally robust Na3GdP2O8: Re3+ (Re = Sm, Dy) phosphors

Highlights: • The novel Sm³⁺ and Dy³⁺ ions doped Na₃GdP₂O₈ phosphors were prepared. • Both orange-red and white lights could obtain with excellent thermal stability. • These phosphors are potential for application in UV/NUV based w-LEDs. With the rapid demand of white light emitting diodes (w-LEDs), studies on the ultraviolet/near-ultraviolet (UV/NUV) light excited phosphors are becoming more and more important. Herein the novel Na₃GdP₂O₈: Re³⁺ (Re = Sm, Dy) phosphors were synthesized through a high-temperature solid-state reaction method. The Sm³⁺-doped Na₃GdP₂O₈ phosphors emitted orange-red light centered at 600 nm, under the NUV excitation at 403 nm. When excited at 350 nm, the Na₃GdP₂O₈: Dy³⁺ phosphors presented a white light emission, including three peaks at 483, 578, and 670 nm, respectively. In addition, both of the Na₃GdP₂O₈: Sm³⁺ and Na₃GdP₂O₈: Dy³⁺ phosphors showed excellent thermal stability at different temperatures, of which the emission intensities at 150 °C could maintain about 75% and 79% of those at room temperature, respectively. These results indicate that the as-prepared phosphors can be considered as potential candidates for applications in UV/NUV excited w-LEDs.