Preparation, characterization, and luminescence properties of double perovskite SrLaMgSbO 6 :Mn 4+ far-red emitting phosphors for indoor plant growth lighting.

Mn 4+ -activated SrLaMgSbO 6 far-red emitting phosphors with double perovskite structure were prepared by traditional solid-state reaction. The research on the crystal structure of the SrLaMgSbO 6 :0.8%Mn 4+ (SLMS:0.8%Mn 4+ ) phosphors showed that the as-prepared sample was made up of two polyhedrons, [SbO 6 ] and [MgO 6 ]. Under the excitation of 333 nm, the SLMS:0.8%Mn 4+ phosphors exhibited an intense far-red emission in the 625-800 nm wavelength range with CIE chromaticity coordinates of (0.733, 0.268), which could match well with the absorption spectrum of phytochrome P FR . The optimal concentration of Mn 4+ ions in the SLMS:Mn 4+ phosphors was 0.8 mol%. Importantly, the as-prepared SLMS:0.8%Mn 4+ phosphors had an internal quantum efficiency of 35%. The thermal stability of SLMS:0.8%Mn 4+ phosphors was also investigated, and the activation energy was found to be 0.3 eV. Thus, the Mn 4+ -activated SLMS phosphors have great potential to serve as far-red emitting phosphors in indoor plant growth lighting.