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Y_2O_3: Eu ~ (3) and Y_2O_2S Luminescent Nanomaterials solvothermal Preliminary Study on Preparation and Luminescence Properties

Author: GuoHuang
Tutor: HongZhangLian
School: Zhejiang University
Course: Materials Physics and Chemistry
Keywords: Nanomaterials Rare earth phosphor Yttria Yttrium oxysulfide Solvothermal synthesis
CLC: TB383.1
Type: Master's thesis
Year: 2006
Downloads: 363
Quote: 2
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Abstract


Rare earth luminescent materials because of their unique luminescent properties and stability of the physical and chemical properties and are widely used in display, LED and other fields, with the development of nano-materials, nano-rare earth luminescent materials, luminescent materials research has become an emerging and hot topics. Based on the review nanometer spectral properties of rare earth luminescent materials, synthesis, application and development status, based on the proposed use of solvothermal synthesis techniques to prepare yttrium oxide nano materials and nano-characterization and study of the Y 2 O 3 : Eu 3 phosphor material properties and luminescent properties, and based on this preliminary study of nano-Y 2 O < sub> 2 S solvothermal synthesis. Paper applications XRD, TEM, DTA-TG, FT-IR, SEM, EDS and PL spectra analysis testing methods, characterization of the different reaction temperature, reaction time, solvent system, and process parameters on the product morphology, size, structure and luminescence Performance. Thesis is divided into three parts: (1) Prepared by solvothermal synthesis of nano YOOH precursor obtained by a low temperature heat treatment of nano-yttria powders, and its synthesis mechanism were analyzed. The results show that a suitable organic solvent can effectively reduce the reaction temperature, to promote crystallization of the precursor dehydration, favor the formation of nanocrystalline; suitable reaction crystal transition temperature is an important condition and size, and is conducive to Y (OH) 3 -YOOH-Y 2 O 3 low-temperature phase transition; Solvothermal products higher activity, can significantly reduce heat temperature. Study obtained preparation Y 2 O 3 nanopowders suitable process conditions: solvothermal reaction temperature was 300 ℃, reaction time 3h, and then by 460 ℃ / 2h heat treatment ; obtain particle size of about 30nm cubic phase Y 2 O 3 powders. (2) Based on the above research synthesis of red europium-doped yttrium oxide nano-phosphors, and fluorescence spectroscopy and other means, focusing on the size of its luminescent properties. The results show that solvothermal synthesis technology enables activator ions uniformly doped, yttrium oxide dopants on the matrix particle size, morphology had no significant effect. With micron compared to commercial standards, and the resulting nano nano phosphors has obvious effects: its ultraviolet excitation peaks appear redshift. Spectral studies show that doping Eu 3 in deviation Y 2 O 3 crystal inversion symmetry, 612nm emission peak located near the corresponding 5 D 0 → 7 F 2 electric dipole transitions; Sui activator doping increases, the luminescence significant change in intensity, peak shape is gradually broadening its critical activator concentrations as high as 11%, significantly higher than micron Y 2 O 3 : Eu 3 Phosphor the critical concentration (6-8%). (3) conducted a preliminary nano-Y 2 O 2 S prepared by solvothermal method, the effects of different sources of sulfur and yttrium source of their product. It was found, Y 2 O 2 S is difficult to prepare a variety of sulfur sources and yttrium source is not conducive Y 2 O 2 S matrix synthesis, which may be attributed to the high stability of the Y 2 O 3 crystal structure due.

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