Morphology and photoluminescence properties of phenolic epoxy resin coating on KH550-modified SrAl₂O₄: Eu²⁺, Dy³⁺ powder in the presence of triarylsulfonium hexafluoroantimonate

In this study, the amino silane coupling agent (KH550)-modified SrAl₂0₄: Eu²⁺, Dy³⁺ phosphor powder coated with phenolic epoxy resin (EOCN) in the presence of triarylsulfonium hexafluoroantimonate catalyst was prepared using the combination of organic–inorganic composite dip-coating and UV curing coating methods. The results of SEM, TEM, and FTIR showed that the organic coating was a layer of compact membrane with a thickness of 20–50 nm, which can be named silane-modified epoxy monomer generated by the KH550 and the EOCN. Furthermore, it was observed that afterglow and spectrum properties of the coated phosphor powder had good long-afterglow luminescence properties, and revealed two emission peaks at 435 nm and 520 nm under the same excitation wavelength of 360 nm, respectively. More interesting, the emitting color of the coated sample was located in the area of cyan light on CIE1931 chromaticity diagram, which led to a slight blue shift rather than the yellow–green color of the pure SrAl₂0₄: Eu²⁺, Dy³⁺ phosphor powder.