Solid solution structural engineering enhances the luminescence of SrMgAl10O17:Cr3+ for agricultural lighting

Abstract

Lead-free non-rare earth oxide phosphors have attracted wide attention due to their environmental protection, sustainability, and potential to replace halides and fluorides in the field of plant lighting. Among them, the Cr3+-excited aluminate phosphor exhibits high brightness, high thermal stability, and far red to near-infrared (NIR) emission due to the influence of the crystal field strength (CFS). This property gives rise to a variety of strategies used to modulate the CFS, for example, single ion substitution, chemical unit co-substitution, etc. Here, we chose the substitution of a single ion, with [BaO6] gradually replacing [SrO6] to form a solid solution. Their structural characteristics and the local structure of Cr3+ are studied and discussed. The device is packaged to evaluate the feasibility of the material for practical application. The prepared phosphor had a bright far-red light emission of 693 nm under blue light excitation, and this spectrum strongly matched the absorption of plant phytochrome PFR. This work provides the design principle of far red light emission activated by Cr3+ aluminate solid solution, which can inspire further research on pc-LED lights for plant lighting.