Investigation of the Luminescence Properties of Dy³⁺ doped Lu₃Ga₂Al₃O₁₂ Phosphors for X-ray Imaging and White LEDs

In this research, Dy³⁺-doped Lu₃Ga₂Al₃O₁₂ phosphor was synthesized by using the combustion method with a solid state reaction at 1500 °C for 12 hours in a furnace. Host materials such as Lu₂O₃, Ga₂O₃, Al₂O₃ and activator such as Dy₂O₃ were used. The crystal structure and the lattice constants were confirmed by using X-ray diffraction. The emission spectrum of the Dy³⁺-doped Lu₃Ga₂Al₃O₁₂ phosphor under excitations by UV light and X-rays showed peaks at 482 nm, 580 nm, 670 nm and 760 nm due to electron transitions from the ⁴F_9/2 to the ⁶H_j orbited. The Lu₃Ga₂Al₃O₁₂:Dy³⁺ phosphor emits blue, green-yellow and red light when excited by UV light and X-rays. The CIE chromaticity diagram for the emission spectrum gives a color close to white, which indicates that Dy³⁺-doped Lu₃Ga₂Al₃O₁₂ phosphor may be a good material for use in a light-emitting diode. The Lu₃Ga₂Al₃O₁₂:Dy³⁺ phosphor has a high sensitivity to X-rays and gamma rays because of its high Z-number (Z_eff = 57) and density. Therefore, the Lu₃Ga₂Al₃O₁₂:Dy³⁺ phosphor can be applied for X-ray imaging in medical fields.