The luminescent properties of GdAlO3:Tb3+ phosphors based on molten salts addition

The (Gd1−xTbx)AlO3 (x = 0-0.12) were obtained through ammonium bicarbonate co-precipitation technology. The pure-phase (Gd1−xTbx)AlO3 with good dispersion could be obtained at relatively lower temperature of 1,000°C. Under optimum UV excitation into 275 nm, the photoluminescence (PL) spectra display a series of 5D4−7FJ transitions of Tb3+ in (Gd1−xTbx)AlO3 system with the strongest green emission at ~546 nm. The overlapping between 8S7/2−6IJ intra f-f transition of Gd3+ and 4f8-4f75d1 transition of Tb3+ at 275 nm suggesting the Gd3+ → Tb3+ energy transfer, and the quenching contents of Tb3+ was found to be ~10 at%. The luminescent property of GdAlO3:Tb3+ phosphor could be further improved with molten salt incorporation. The optimal composition of molten salts was determined to be the mixture of NaCl/Na2SO4 (5 wt% NaCl), and the mass ratio of mixture molten salts to precursor was 2:1. The relationship between the luminescent property and molten salts composition were studied in detail.