A bifunctional phosphor Sr3Sn2O7:Eu3+: Red luminescence and photochromism properties

In this work, we report a bifunctional phosphor Sr3Sn2O7:Eu3+ which shows red luminescence and photochromism properties. All as-prepared Sr3Sn2O7:Eu3+ samples were studied systematically by X-ray diffraction, photoluminescence spectra, diffuse reflection spectra, thermoluminescence glow curves. The optimum doping concentration of Eu3+ for the PL emission was determined to be 0.2. Concentration quenching and thermal quenching in photoluminescence (PL) emission were discussed in detail. Meanwhile, the material can change its surface color from white to brown under ultraviolet (UV) (254 nm) irradiation. The colored sample is bleached by blue light (400 nm) irradiation or heat treatment. The coloration-bleaching process is reversible, which makes it potential to be used in the field of photo switchers, erasable optional memory medial and sensors. Finally, a model is proposed on the basis of experimental results to discuss the mechanism of photoluminescence and photochromism in Sr3Sn2O7:Eu3+ in detail.