Effect of H3BO3 flux on the morphology and optical properties of Sr2MgAl22O36:Mn4+ red phosphors for agricultural light conversion films

H₃BO₃ was added during the preparation of Sr₂MgAl₂₂O₃₆:Mn⁴⁺ phosphors by a high-temperature solid-state reaction method. The influence of H₃BO₃ flux on the crystal structure, particle morphology and photoluminescence properties of the Sr₂MgAl₂₂O₃₆:Mn⁴⁺ phosphors was investigated by employing X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy, respectively. The results indicate that adding H₃BO₃ flux can improve the luminescence intensity and morphology, and reduce the synthesis temperature of the Sr₂MgAl₂₂O₃₆ phosphor. The formation temperature of pure-phase Sr₂MgAl₂₂O₃₆ was significantly decreased when H₃BO₃ flux as introduced. The excited state lifetime of the Sr₂MgAl₂₂O₃₆:1.2 mol% Mn⁴⁺ phosphor by the addition of 2.0 wt% H₃BO₃ was ~1.02 ms. We demonstrated the potential of these phosphors to enhance sunlight harvesting by agricultural light conversion film testing. We propose that films containing the Sr₂MgAl₂₂O₃₆:1.2 mol% Mn⁴⁺ phosphor can be applied to increase the production of agricultural plants.