Synthesis and characterization of a far-red-emitting Sr2ScNbO6: Mn4+ phosphor for short-day plant cultivation

Far-red phosphors with higher thermal stability and exhibit excellent spectral compatibility with the far-red light phytochrome (PFR) absorption spectrum. They are currently a research hotspot and widely applied in plant growth lamps. In this study, we have prepared a Mn4+-activated Sr2ScNbO6 far-red phosphor by using the high temperature solid phase method in air. The strongest excitation center of the Sr2ScNbO6: Mn4+ phosphor was located at 365 nm. Due to the 2Eg→4A2 g transition, this phosphor generates strong deep-red light at 703 nm, which significantly overlaps with the absorption spectrum of plant phytochrome PFR. The variable temperature photoluminescence (PL) emission spectra from 303 K to 503 K confirmed this phosphor possesses relatively good thermal stability. In addition, the concentration quenching effect and the thermal quenching mechanism are studied in detail. The results demonstrate that Sr2ScNbO6: 0.4 % Mn4+ phosphor provides a novel choice for the far-red phosphor required for short-day plant cultivation.