Dynamic Phosphorescent Color of the Warm-Toned Long-Lasting Phosphor Composite PMMA/RECC@SAOED

A series of warm-toned long-lasting phosphor composite PMMA/RECC@SAOED were prepared by coating various concentrations of coumarin type red-emitting color converter (RECC) on the surface of yellowish-green emitting long-lasting phosphor SrAl2O4:Eu2+, Dy3+ (SAOED) with the aid of PMMA encapsulation. The specific dynamic variation process of the phosphorescent color of PMMA/RECC@SAOED composites in darkness was systematically investigated. Results indicate that the perceived phosphorescent color of PMMA/RECC@SAOED undergoes an overall gradual shift toward blue in darkness after the removal of the excitation light, and the extent of this shift increases gradually with the increase of RECC. This work provides new perspectives in producing warm-toned emitting phosphors and investigating luminescent color.