Structural and luminescence properties of Y2O3:Eu3+red phosphor by incorporation of Ga3+ and Bi3+ions

Abstract The cationic substitution of Y3+simultaneously with Bi3+/Ga3+ ions on the crystal structure of the Y2O3:Eu3+ phosphor and its effect on the structure, the luminescence and thermoluminescence properties was investigated. Four samples were prepared by using a sol-gel combustion method. The substitution of Bi3+/Ga3+ ions modified the Y2O3:Eu3+ phosphor structure, which showed a transition phase structure. In addition, the presence of Bi3+/Ga3+ ions simultaneously in the Y2O3:Eu3+ phosphor structure affected the optical properties. The excitation at 305 nm gave the characteristic emission peaks of the Eu3+ ions with a remarkable increase in the intensity of the peak at 628 nm compare to the same peak that was excited using the Bi3+excitation at 330 nm. The Judd-Ofelt theory was used to estimate the photometric parameters. The TL glow curves of UV-irradiated samples showed a low temperature peak at about 402 K and a high temperature peak at 543 K. A significantly change in the TL intensities for the different dopants in the Y2O3 was observed. The TL kinetics parameters were calculated by a deconvolution computer fitting program using the general order kinetic equation. Different dopants in the Y2O3 was observed with defect levels ranging from 0.8 to 1.8 eV.