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Study on the Iuminescent Properties of Rare-earth Ions Doped NaYF4 Nanoparticles and Glass-ceramics

Author: JieJunHua
Tutor: QiuJianRong
School: Zhejiang University
Course: Materials Science and Engineering
Keywords: Nanocrystalline Polarized Luminescence Mid-infrared light - emitting Optical fiber temperature sensing
CLC: TQ171.11
Type: Master's thesis
Year: 2011
Downloads: 135
Quote: 0
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Abstract


Nanomaterials exhibit many unique properties due to its unique quantum size effect, small size effect, surface effect, macroscopic quantum tunneling effect and dielectric confinement effect, have broad applications in catalysis, medicine, biomarkers, communications prospects. Already the oxyfluoride glass containing nanocrystalline rare earth ions, transition metal ions, such as luminescence enhancement reported these ion doped into a one-dimensional structure of the material may find its special nature. Excellent optical properties of the material with the penetration of nanoscience and nanotechnology in various traditional areas, as well as the rare-earth ion doped nanoparticles recent flurry of the spectroscopic properties of the rare-earth ions and its potential applications. Research topics proposed in this paper is based on the optical properties of doped nanocrystalline rare earth ions, including the following three parts: 1. Due to the one-dimensional one-dimensional orientation of the material and the confinement, if introduced in the one-dimensional nanomaterials luminous active center, the light emitting from the one-dimensional material may be linearly polarized, one-dimensional line polarized light source, sensor, light detectors, etc. can be applied. Firstly, a simple and non-toxic solvent thermal method, discussion of the reaction conditions, the preparation of the size, morphology controlled six-party NaYF4 nanoparticles, and the introduction of the single nanorod light-emitting active center 980nm continuous Yb3 / Tm3. observed Yb3 / Tm3 of doped NaYF4 nm laser excitation, stick strong upconversion visible luminescence. The optical polarization properties of single nanorod the whole polarized emission rate was 0.31. Calculate different emission wavelength of 440nm, 635nm, 703nm polarizing light-emitting rate, respectively 0.37,0.17,0.97. Polarized Luminescence of the the Tm3 ions of different emission wavelengths different explanation is still insufficient, but also worthy of further study. NaYF4 nano-particles is expected to be used to prepare a one-dimensional line polarized light source. Rare earth ion doped glass oxyfluorophosphoric integrated the advantages of glass and fluoride nanocrystals, both have glass easily prepared, easily drawn into the nature of the fiber, both in nanocrystalline superior optical properties. This article was prepared Tm3-Yb3 codoped containing the CaF2 nanocrystals oxyfluoride transparent glass, using XRD characterization methods by HREM, SAED, absorption spectroscopy, steady-state fluorescence spectra of Tm3 in infrared glass and glass The emission intensity is observed compared to the crystallized glass in the infrared light emitting stronger, when the the Yb3 concentration of 8 mol%, the crystallized glass in the infrared light emitting enhanced twice. Simultaneously under different temperatures in the infrared-emitting tests show that the effects of ambient temperature in the base body can be ignored. JO theory to calculate the optical parameters of Tm3 ions in the glass and glass, result that more Tm3 mid-infrared laser output in the glass-ceramic. The fluorine-oxygen glass system the relative fluoride glass is more suitable for mid-infrared laser output matrix. 3 technology optical temperature sensor based on the fluorescence intensity ratio due to high accuracy, low cost, simple detection, less susceptible to external factors become a new hotspot. It requires that the rare earth ion doping in a suitable matrix, and the strong excitation of the excitation light source of low power can be obtained on the switching signal. Fluoride oxygen crystallized glass both oxide glass of high temperature and the low phonon energy of the fluoride crystal, the advantages of high efficiency of rare earth ions emitting. This article Yb3-Er3 codoped the SrF2 glass, Er3: 2H11 / 2 → 4I15 / 2,4 S3 / 2 → 4I15 / 2 under different ambient temperature fluorescence characteristics, based on the fluorescence intensity ratio R (I522/I540) fitting the temperature dependence of the experimental data, calculated according to the result of fitting different temperature sensitivity R 350K and sensitivity R reaches a maximum for 0.0024 / K. Fluorescence intensity ratio R with the pump power change is essentially the same, the results show that the the SrF2 glass to fit in as a fiber optic temperature sensor.

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