VUV photoluminescence of green-emitting GdPO4:Tb,M (M: Al, Zn) synthesized by ultrasonic spray pyrolysis

We successfully synthesized (Gd0.94−xTb0.06Mx)PO4 (M: Al and Zn; 0 ≤ x ≤ 0.06) green phosphors by ultrasonic spray pyrolysis and investigated their photoluminescence characteristics. The synthesized (Gd0.94−xTb0.06Mx)PO4 phosphor powders showed a spherical morphology and a smooth surface. The phosphors emitted a green light due to the transition from 5D4 to 7Fj of Tb3+ (j = 3–6) at 489, 544, 585, and 621 nm, respectively. The partial incorporation of Al or Zn for Gd up to x = 0.45 in (Gd0.94Tb0.06)PO4 phosphors yielded a significant rise in the emission intensity. The (Gd0.895Tb0.06Al0.045)PO4 and (Gd0.895Tb0.06Zn0.045)PO4 phosphors showed 31 and 13% stronger emission intensity at 544 nm, respectively, compared to (Gd0.94Tb0.06)PO4 phosphor.