Double relaxation emission of Sn2+ activator in tin fluorophosphate glass for optoelectronic device applications

Abstract In this work, in addition to the presence of cool white luminescence under ultraviolet illumination, after removing illumination, transitory phosphorescence (about ∼1s) was observed in pure tin fluorophosphate glass prepared by traditional melting methods. By dynamic spectroscopy analysis, its novel coexistence of fluorescence and phosphorescence phenomenon was attributed to the double relaxation behavior of T1→S0, and the glass composition was considered to be an important factor affecting the S1/S1’→T1 conversion rate of Sn2+ activator. The electron paramagnanetic resonance test suggested that the oxygen vacancy surrounded in Sn2+ activator captured electronics to form the F+-like center. As this defect center as energy trap, the brand-new triplet (T1)-singlet (S0) relaxation band model of Sn2+ activator was proposed to describe this double relaxation emission. It was demonstrated that tin fluorophosphate glass possessed excellent potential in the application of light-responsive optoelectronic devices and phosphor-converted white light-emitting diodes (pc-WLED).