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.