Efficient Blue to Red Afterglow Tuning in a Binary Nanocomposite Plastic Film.

Colorful spectra are important for the diverse applications of persistent phosphors. A color conversion concept is developed to obtain abundant persistent luminescence color by mining capacities of known persistent phosphors with the most efficient persistent properties. Here, SiO₂/Sr₂MgSi₂O₇:Eu,Dy nanoparticles are chosen as a blue persistent luminescence donor nanophosphor, while ultrafine CaAlSiN₃:Eu is utilized as a red conversion phosphor to tune the persistent luminescence spectra from blue to red. The red afterglow emission can persist for more than 5 h. The decay of the red afterglow follows nearly the same kinetics as that of the blue one. Continuous color tuning can be successfully obtained by simply changing the mass ratio of the donor/conversion phosphor pair. This color conversion strategy may be significant in indicating numerous persistent/conversion nanocomposites or nanostructures and advance the development of persistent phosphors in diverse fields which need colorful spectral properties.