Rare Earth ion doped gadolinium molybdate phosphor Synthesis

Title: Rare Earth ion doped gadolinium molybdate phosphor Synthesis and Spectroscopic Properties of
　　Author: Wan Jing
　　Degree-granting unit: Dalian Maritime University
　　Keywords: white LED;; gadolinium molybdate phosphors;; concentration quenching;; decay lifetime;; color coordinates
　　Summary:
　　In recent years, with a white LED for energy saving, environmental protection and many other advantages more and more people's attention, and gradually become the mainstream lighting products. White LED's to achieve there are many ways currently more promising approach is phosphor light conversion method, which uses blue or near-UV LED excitation Neodymium Magnets phosphor and white light. Molybdate ions can effectively absorb the near-UV, and can effectively transfer energy absorbed to the activator ions, so the papers were single doped and codoped gadolinium molybdate spectral properties of phosphors, white light to explore its implementation the possibilities.
　　We use the traditional high temperature solid state reaction synthesis of single-doped, respectively, and co-doped gadolinium molybdate single doped phosphor, by XRD, SEM, fluorescence spectroscopy, fluorescence dynamics testing and calculation methods such as color coordinates with different concentrations of activator ions in the matrix material in gadolinium molybdate luminescence properties and energy transfer behavior research.
　　Through the doped gadolinium molybdate phosphor luminescence analysis shows that the system can be effective near-UV excitation, and high energy transfer efficiency, high concentrations of the phenomenon of concentration quenching occurs when, because of Dy3 + between the existence of cross-relaxation phenomena and the electric dipole - dipole interaction. Blue and yellow can be made, so they have the possibility to achieve white light, but its lack of red parts, so the color is poor.
　　To compensate for the single-doped gadolinium molybdate red phosphor composition of the lack of, we introduce a doped luminescent centers. http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets By spectral analysis of the co-doped gadolinium molybdate phosphor luminescence properties, found in the near ultraviolet region, between the Mo-O and transfer energy from the bridge, the introduction of Mo-O to increase the energy pathways, and energy delivery more efficient. Mixed with a certain amount can be realized with a certain proportion of blue, yellow and red emission, while achieving the red and white light emission compensation.
　　Synthesized a series of variable concentrations of gadolinium molybdate single doped phosphor, by analyzing the excitation and emission spectra and fluorescence decay curve, observed the interaction between the two electric dipole cross relaxation process, and on the level the energy of exchange interaction between the migration behavior is not observed, mainly because the compounds we studied concentration range of the distance between small enough. Meanwhile, the color coordinates calculated that the emission color coordinates with the sample concentration changes.
　　Degree Year: 2010