Preparation of color tuned highly emissive long-lasting phosphor with warm-toned emitting color based on coating red-emitting coumarin fluorescent dye color converter and PMMA on SrAl2O4:Eu2+, Dy3+ phosphor

A color tuned highly emissive long-lasting phosphor PMMA/RECC@SAOED with warm-toned emitting color was prepared by coating a red-emitting coumarin fluorescent dye color converter (RECC) and PMMA on the surface of green emitting SrAl2O4:Eu2+, Dy3+ (SAOED) phosphors. After being characterized by SEM, FT-IR spectra, photoluminescence (PL) spectra, CIE color coordinates and afterglow decaying curve, the results demonstrated the feasibility of the prepared RECC as the warm-toned color converter for the green-emitting SAOED. After being coated with color converter, the PL spectra of PMMA/RECC @SAOED consisted of two broad bands with two emission peaks at 520 nm and 610 nm, and the intensity of spectra in the range of (576-700) nm increased gradually with the increase of color converter content. The emitting color of the PMMA/RECC@SAOED could be easily controlled by adjusting the concentration of color converter, and it moved to yellow, orange and reddish when the concentration of color converter was added to 0.3%, 0.5% and 0.9%.