Scanning Micrograph Images Research Articles

Photoluminescence and long persistent luminescence properties of a novel green emitting phosphor Sr3TaAl3Si2O14:Tb3+

A series of green emitting persistent phosphors Sr3TaAl3Si2O14:Tb3+ were synthesized via a conventional solid-state reaction method. These phosphors show a green persistent luminescence dominated at ~542 nm at room temperature after irradiated by 254 nm ultraviolet light for minutes. X-ray diffraction, scanning micrograph images, photoluminescence spectra, decay curves, afterglow spectra and thermal luminescence were performed to investigate the physical properties of the persistent phosphors. The influence of Tb3+ concentrations on the photoluminescence and long persistent luminescence properties was studied. The optimal concentration of Tb3+ ions for the best afterglow characteristic was experimentally to be 0.5 mol%. A feasible model was proposed on the basis of experimental results to discuss mechanism of long afterglow in Sr3TaAl3Si2O14:Tb3+ in detail.

Luminescent properties of Tb3+-doped Ca2SnO4 phosphor

The novel green light emitting phosphors Ca2SnO4:Tb3+ were synthesized via a traditional solid state reaction method. All as-prepared phosphors were studied systematically by X-ray diffraction, scanning micrograph images, photoluminescence spectra, decay curves, afterglow spectra and thermoluminescence glow curves. The cross-relaxation of two adjacent Tb3+ ions led to the main emission peaks locate at 483 and 545nm under excitation of 255nm. The CIE chromaticity coordinates are x=0.197 and y=0.279. The intensities of photoluminescence and afterglow are dependent on the concentration of Tb3+ ions. The optimal concentration of Tb3+ ions for the best afterglow characteristic was experimentally to be 0.1mol%. After irradiation by 254nm, the duration of afterglow can last more than 3h. The mechanism of long afterglow in Ca2SnO4:Tb3+ is also discussed.