Synthesis And Luminescence Properties Of Gallate

The development of flat panel display devices such as field emission displays (FEDs) and vacuum fluorescent displays (VFDs) requires highly efficient cathodoluminescent materials. It is important for the bright and efficient phosphor to choose the group material. Oxide phosphor is noticed because of the excellent heat stability. Gallate have high chemical stability and narrow band-gap, so it fit to be used as phosphor. This paper reported the synthesis of phosphor ZnGa₂O₄ and ZnGa₂O₄ and discussed the influences of activator, sensitizer, calcined temperatures, duration, and concentrations of activator on luminescent properties. Phase compositions and luminescent properties of the phosphors were investigated and detected by using XRD and phosphor luminometer (PL). The reaction process is analyzed by the TG-DTA and the appearance of the phosphor is observed by SEM.(1) ZnGa₂O₄:Eu phosphor is synthesized by the sol-gel process , which is completely reacted with ratio of Zn : Ga=l : 4．The main peak at 610 nm can be ascribed to ⁵D₀→F of Eu³⁺ , corresponding to red light. Eu³⁺ ion occupies a site with lacking inversion symmetry in ZnGaO host lattice. It could be change the luminescent intensity by(2) The Eu³⁺ doped SrGa₂O₄ phosphor was prepared with the conventional solid state reaction method. The phase composition was characterized by powder X-ray diffractometry. The result shows that the producing powder belongs to monoclinic crystal system with its lattice constants: a=9．43(?), b=9．00(?), c=8．39(?),β=89．06°, and with space group P21/ n (No. 14) . The excitation and emission spectra were measured. The main peak at 610nm can be ascribed to the electric dipole transition ⁵D₀→⁷F₂, which indicates that Eu³⁺ occupies a site lacking inversion symmetry. The peaks at 590nm and 610nm transition emission split to two peaks respectively, ⁵D₀→⁷F₁, (586, 597nm) and ⁵D₀→⁷F₂ (609, 615nm) due to the crystal-field in the conditions of concentration of Eu with more than 1%. The strength ratio of two parts for the splitting peak ⁷F₂can be changed according to the concentration of Eu.(3) The phosphor of SrGa₂O₄: Eu : Gd was prepared with the conventional solid-state reaction method. Gd is sensitizer of Eu, there is energy transform between Gd and Eu. The main peak at 613 nm can be ascribed to ⁵D₀→⁷F₂ of Eu³⁺ . The luminescent intensity is improved.(4) The Zn_0．5 Sr_0．5 Ga₂O₄ : Eu prepared by solid-state method. The results of the experiment show that the produced powder is the mixture of ZnGa₂O₄ and SrGa₂O₄．...