nanocrystalline rare earth oxides and fluorides-conversion fluorescence spectra of Design

Title: nanocrystalline rare earth oxides and fluorides-conversion fluorescence spectra of DesignAuthor: Chen GuanyingDegree-granting unit: Harbin Institute of TechnologyKeywords: nanocrystalline;; earth;; conversion;; Spectrum DesignSummary:

Continuous optical frequency conversion in medical detection and coding, photodynamic therapy of human internal diseases, the development of continuous short-wavelength lasers, three-dimensional imaging, display and other aspects of good application prospects. However, the fluorescence emission in the conversion there are still bare, such as conversion efficiency is not high, a Neodymium Magnets serious shortage of human design spectrum, the UV emission is rarely up-conversion design issues, which affect the conversion in the medical and photonics applications . In this paper, rare earth oxides and fluorides for the study, designed in-conversion fluorescence spectroscopy, fluorescence enhancement, ultraviolet upconversion fluorescence acquisition, and application in medicine and other areas of the systems.

Carried out oxide and white monochrome design of upconversion luminescence studies. By adjusting the doping concentration of Yb3 ions in the 980 nm laser excitation, to obtain a single red and single green upconversion fluorescence; power relations through the analysis of the excitation and fluorescence, fluorescence spectroscopy, and theoretical analysis of rate equations to clarify the color on conversion emission mechanism; by defining "rejection ratio" concept, put forward the launch of the color-conversion of the evaluation criteria; by Er3, Tm3, and Yb3 reasonable ratio, obtained over a wide power range of 980 nm laser excitation of nanoparticles -conversion emission of white light; through experiments and theoretical analysis, to clarify the white-conversion emission mechanism.

Enhanced upconversion luminescence of oxides method were studied. Conversion by rare-earth nano-materials, the further introduction of Li-ion doping, won two orders of magnitude enhancement of the upconversion luminescence. Through a large number of experimental and theoretical analysis, its enhanced mechanism: Li-ion introduction to mass in the lattice, and thus modification of the lattice field, so that the relevant energy levels of rare earth ions increase the life span, in order to achieve a conversion luminescence enhancement. Experimental results show that this enhancement applies not only to different upconversion luminescence of rare earth ions enhanced, but also for rare-earth ions in different matrices upconversion enhancement. That this enhancement is universal.

Of ultraviolet upconversion luminescence were studied. In Yb3 / Tm3-doped oxide, in the 980 nm laser excitation near 300 nm observed ultraviolet upconversion luminescence, fluorescence excitation light and power relations that the UV radiation for the five-photon and six-photon process; made on it conversion luminescence mechanism. Proposed and http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets confirmed Yb3 / Er3-doped oxide in the blue and ultraviolet fluorescence upconversion luminescence mechanism. Observed under 980 nm laser excitation 240-490 nm band Yb3 / Ho3-doped fluoride upconversion emission, and confirmed the proposed mechanism for its light and saturation explains the observed phenomenon. Using sensitized Ho3 ion Gd3 ion design was NaGdF4: Yb3 / Ho3 nanocrystals Gd3 ion ultraviolet upconversion, and explains the mechanism of its luminescence. Observed in doped fluoride sensitized Er3 and Er3 Gd3 ions near vacuum ultraviolet upconversion and super-saturation effects, and explain the proposed light-emitting mechanism.

Preparation of nanoparticles for medical, upconversion, and medical applications have been studied. Using wet chemical methods, to explore fluoride nanoparticles of different sizes and cladding of the preparation process, preparation of controlled size and morphology of nano-materials and fluoride fluoride core-shell structure nanomaterials. By Ce3, Yb3 ion doping concentration adjusted to obtain a fluoride nanoparticles excited by infrared light in the red light on the conversion of radiation, and clarify the regulatory mechanism of its spectrum. Design of the core-shell structure of fluoride nanoparticles, to obtain enhanced upconversion luminescence, and explained the proposed conversion on the enhancement mechanism. Preparation of nano-materials using fluoride, demonstrated that in the tissue fluid in upconversion imaging spatial resolution in imaging is much better than the traditional fluorescent labeling of fluorescence imaging. Through animal experiments, we demonstrated the preparation of fluoride nanoparticles can be no background, multicolor, in vivo imaging.Degree Year: 2009