Novel far-red emitting phosphor Mn4+-activated BaLaLiWO6 with excellent performance for indoor plant cultivation of light-emitting diodes

The far-red oxide phosphors doped with Mn 4+ ions are constantly investigated for plant cultivation of light-emitting diodes (LEDs) due to their emission bands matching well the absorption region of phytochromes in plants. Herein, a novel far-red emitting phosphor of BaLaLiWO 6 (BLLW) doped with Mn 4+ ions was successfully prepared for plant cultivation. The Rietveld-refined lattice parameters and surface micromorphology of the samples were investigated. The theoretical values of the energy gap for the perfect BLLW matrix were calculated by density functional theory and the experimental values obtained based on the absorption spectra were compared. In addition, the samples can be efficiently excited by ultraviolet and blue light, and emit intense far-red light with a central wavelength of 708 nm. Furthermore, the crystalline field effect and concentration quenching mechanism of Mn 4+ ions in the BLLW matrix were explored. Satisfactorily, the internal quantum efficiency, color purity, and activation energy of the phosphor were as high as 48.38%, 99.6%, and 0.53 eV, respectively. Meanwhile, the effects of synthesis temperature and Ca 2+ ions co-doping on the luminescence intensity of the samples were studied. Finally, the far-red LEDs devices were prepared for plant cultivation by combining the phosphor with 460 nm LEDs chips. • Novel BaLaLiWO 6 : Mn 4+ far-red double perovskite phosphors were synthesized. • The activation energy and color purity of the samples were as high as 0.53 eV and 99.6%, respectively. • The IQE value of the phosphor by local lattice tuning was as high as 48.38%. • The LEDs devices for plant cultivation were prepared with the phosphor.