Effect of Bi³⁺ ion concentration on crystal structure and luminescent properties of blue-green-emitting Y₂O₃:Bi³⁺ phosphors

Blue-green-emitting Y₂O₃: xBi³⁺ (x = 0.25-1.50 mol.%) phosphors were synthesized by a solution combustion method followed by high temperature annealing. The effect of Bi³+ ion concentration on the crystal structure and photoluminescence performance of the phosphors were investigated. The results show that the cell parameter and cell volume of Y₂O₃ host were increased with the Bi³⁺ concentration, and all the phosphor powders exhibited porous lamellar structure with the width of ~500 nm. The emission spectra of the phosphors (l_ex = 335 nm) consist of three broadband emission spectra centered at 370 nm (³A_u → ¹A_g), 410 nm (³E_u → ¹A_g) and 486 nm (³B → ¹A), respectively. The phosphor exhibited the optimal luminescence performance at x = 0.50% and the dipole-dipole and quadrupole-quadrupole interactions among Bi³+ ions could lead to the concentration quenching. The color coordinates of Y₂O₃:0.50%Bi³⁺ were (0.1595, 0.2250), indicating that the as-synthesized blue-green phosphors have a broad application prospect in the field of white light-emitting diodes.