Effect of H 3 BO 3 flux on the morphology and optical properties of Sr 2 MgAl 22 O 36 :Mn 4+ red phosphors for agricultural light conversion films

Abstract H 3 BO 3 was added during the preparation of Sr 2 MgAl 22 O 36 :Mn 4+ phosphors by a high-temperature solid-state reaction method. The influence of H 3 BO 3 flux on the crystal structure, particle morphology and photoluminescence properties of the Sr 2 MgAl 22 O 36 :Mn 4+ phosphors was investigated by employing X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy, respectively. The results indicate that adding H 3 BO 3 flux can improve the luminescence intensity and morphology, and reduce the synthesis temperature of the Sr 2 MgAl 22 O 36 phosphor. The formation temperature of pure-phase Sr 2 MgAl 22 O 36 was significantly decreased when H 3 BO 3 flux as introduced. The excited state lifetime of the Sr 2 MgAl 22 O 36 :1.2 mol% Mn 4+ phosphor by the addition of 2.0 wt% H 3 BO 3 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 Sr 2 MgAl 22 O 36 :1.2 mol% Mn 4+ phosphor can be applied to increase the production of agricultural plants.