Design and realization of an orange–red phosphor samarium-activated diphosphate Na5Bi1−xSmx(P2O7)2

Recently, rare-earth-activated phosphors have been excessively studied for applications in field of white light-emitting diodes (W-LEDs). In this work, a series of Sm3+-doped Na5Bi(P2O7)2 phosphors have been synthesized via traditional high-temperature solid-state reaction method. The purity and phase structure were verified by powder X-ray diffraction (XRD) analysis. Owing to the 4G5/2→6H7/2 transition of Sm3+, Na5Bi1−xSmx(P2O7)2 phosphors show intense orange–red emission centered at 600 nm under near-UV light (403 nm) excitation. The 4% Sm3+ ion is the optimum doping concentration. The concentration quenching dominant mechanism is the d−d interaction. Moreover, phosphors Na5Bi0.96Sm0.04(P2O7)2 show good thermal stability, restraining 79.4% at 150 °C of that measured at 25 °C. The CIE coordinates of phosphor Na5Bi0.96Sm0.04(P2O7)2 were calculated to be (0.573, 0.414). Therefore, phosphor Na5Bi1−xSmx(P2O7)2 could be potentially used as an orange–red phosphor for W-LEDs.