Tunable Luminescent Properties and Multifunctional Imaging Applications of (GdR)OS:Tb (R = Y, La) Phosphor and Screen.

GdOS:Tb phosphor screens are widely used in image intensifiers, computed tomography, and neutron imaging. To improve the luminescent properties and thermal stability, (GdR)OS:Tb (R = Y, La) ( = 0, 0.05, 0.15, 0.25, and 0.35; = 0.02, 0.04, 0.06, 0.08, and 0.10) phosphors were successfully prepared by the carbothermal reduction method. The luminescent spectra showed that the optimum concentrations of Tb ions were 6 and 4 mol % when excited by 292 nm UV light and cathode ray, respectively. The emission wavelengths mainly peaked at 489 and 544 nm. It was found that the introduction of Y ions could improve the luminescent intensity, and the luminescent intensity of (GdY)OS:0.06Tb was the highest at = 0.25, while La ions played the opposite role. Then, the thermal stability also improved, and the emission intensities of GdOS:0.06Tb, (GdY)OS:0.06Tb, and (GdLa)OS:0.06Tb phosphors at 423 K decreased to 66.22%, 68.23%, and 76.10% of the emission intensities at 303 K, respectively. Finally, the (GdY)OS:0.06Tb phosphor screen was successfully prepared by the gravity deposition method and could be well imaged under UV light and cathode ray excitation with a CMOS camera. In summary, this study demonstrates that (GdR)OS:Tb (R = Y, La) is a phosphor with excellent luminescent and thermal stability properties and has great potential for application in the field of low-level-light night vision, nondestructive testing, and medical imaging.