Luminescent Properties of Eu3+-Doped BaLn2ZnO5 (Ln=La, Gd, and Y) Phosphors by the Sol–Gel Method
Abstract:Three series of Eu3+-doped BaLn2−xEuxZnO5 (Ln=Y, Gd, and La) phosphor powders were prepared by the sol–gel process. Parameters that affect the photoluminescence (PL) intensity of phosphors were investigated in detail. The phase formation and identification of samples were characterized by thermogravimetry and differential thermal analysis and X-ray diffraction (XRD), respectively. The morphologies of the phosphor particles and the spectra of the as-prepared phosphors were investigated by means of field-emission scanning electron microscopy (FE-SEM) and PL measurements. The XRD results reveal that the sample adopts a tetragonal structure for BaLa2−xEuxZnO5 and the other two samples adopt an orthorhombic structure in our experimental ranges, and the formation temperature of the pure phase increases with the decreasing of the radius of Ln3+ ions. The FE-SEM images indicate that the size and the shape of phosphor particles are regular. The PL spectra of phosphors BaLn2−xEuxZnO5 (Ln=Y, Gd, and La) show the characteristic emissions of Eu3+. And the emission color of phosphors BaLn2−xEuxZnO5 (Ln=Y, Gd) could be tuned from white to red by changing the concentration of Eu3+, but the BaLa2−xEuxZnO5 only shows red emission and was independent to the concentration of Eu3+.
Document Type: Research Article
Affiliations: Wuhan National Laboratory for optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Publication date: June 1, 2010