A novel Sm2+ doped broadband far-red BaAl2Si3O4N4: Sm2+ phosphor for plant lighting applications

Abstract

Far-red light plays a crucial role in the field of plant lighting. Herein, a novel far-red phosphor BaAl2Si3O4N4: Sm2+, which can be effectively excited by blue light, was successfully prepared by high-temperature solid-state reaction. The PL spectrum show a broadband emission range from 600 nm to 950 nm (FWHM = 120 nm), which is well matched with the absorption of PFR in plant. In BaAl2Si3O4N4: Sm2+, the Ba2+ are coordinated with three N and six O atoms. When the rare earth ion of Sm2+ was doped into the host lattice, Ba2+ was partially replaced by Sm2+. The low temperature PL spectra at 8–80 K were studied in detail. It was found that the PL spectra at low temperature were composed of some sharp lines and broadband superposition, which corresponding to the 5D0-7FJ (J = 0–4) energy level transition of Sm2+. It is shown that the broadband emission of the phosphor was caused by the broadening of the 4f55 d1 energy level due to the strong crystal field effect. The thermal stability analysis showed that the luminescence intensity of BaAl2Si3O4N4: Sm2+ at 150 °C still maintains 62.7 % of that at room temperature, showing excellent thermal stability. All results indicate that BaAl2Si3O4N4: Sm2+ phosphor has important potential applications in the field of plant lighting.