Preparation, characterization, and luminescence properties of double perovskite SrLaMgSbO6:Mn4+ far-red emitting phosphors for indoor plant growth lighting

Abstract

Mn⁴⁺-activated SrLaMgSbO₆ far-red emitting phosphors with double perovskite structure were prepared by traditional solid-state reaction. The research on the crystal structure of the SrLaMgSbO₆:0.8%Mn⁴⁺ (SLMS:0.8%Mn⁴⁺) phosphors showed that the as-prepared sample was made up of two polyhedrons, [SbO₆] and [MgO₆]. Under the excitation of 333 nm, the SLMS:0.8%Mn⁴⁺ 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 Mn⁴⁺ ions in the SLMS:Mn⁴⁺ phosphors was 0.8 mol%. Importantly, the as-prepared SLMS:0.8%Mn⁴⁺ phosphors had an internal quantum efficiency of 35%. The thermal stability of SLMS:0.8%Mn⁴⁺ phosphors was also investigated, and the activation energy was found to be 0.3 eV. Thus, the Mn⁴⁺-activated SLMS phosphors have great potential to serve as far-red emitting phosphors in indoor plant growth lighting.