Molten salt synthesis, energy transfer, and temperature quenching fluorescence of green-emitting beta-Ca2P2O7:Tb3+ phosphors

摘要

Tb3+-doped beta-Ca2P2O7 phosphors were successfully prepared via a simple surfactant-free molten salt method for the first time and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and photoluminescence. The results of XRD and SEM suggest that the products belong to pure beta-Ca2P2O7 nanoparticles with average particle size of about 88.6 nm. Under the UV light excitation, the as-prepared beta-Ca2P2O7:Tb3+ phosphors exhibit green emission, which corresponds to the characteristic emissions of Tb3+ ion. The optimal doping concentration of Tb3+ ions in beta-Ca2P2O7 phosphors was confirmed to be abound 10 mol% and the exchange interaction is responsible for energy transfer between Tb3+ ions in beta-Ca2P2O7 phosphors. The fluorescent lifetime of D-5(4) level of Tb3+ in beta-Ca2P2O7 phosphors decreases with the increase of Tb3+ ions concentration because of self-generated quenching process, which was confirmed by Auzel's model. The thermal quenching behaviors of beta-Ca2P2O7:Tb3+ nanophosphors were also studied and the activation energy was deduced to be 0.265 eV.