Rare earth doped upconversion nanocrystals BaYF_5 Synthesis and Characterization

Title: Rare earth doped upconversion nanocrystals BaYF_5 Synthesis and Characterization
　　Author: Qiu Hailong
　　Degree-granting unit: Harbin Institute of Technology
　　Keywords: BaYF_5 nanocrystals;; conversion;; rare earth doped
　　Summary:
　　Rare-earth doped up-conversion materials in three-dimensional imaging, detection and medical coding, internal diseases, the body photodynamic therapy, the development of continuous short-wavelength lasers and other aspects of good application prospects. However, the fluorescence emission in the conversion, there are still many problems, thus affecting the rare earth magnets up-conversion in the medical and photonics applications.
　　In this paper, BaYF5 nanocrystals as the research object, the conversion control nanocrystal size and morphology, up-conversion fluorescence spectra and fluorescence enhancement and other design aspects of the basic research. Discusses the use of EDTA as a chelating agent, Hydrothermal BaYF5 different size and morphology of nanocrystals. The synthesis of spherical nano-particle size distribution more uniform, monodisperse good and strong upconversion luminescence. X-ray diffraction (XRD), transmission electron microscopy (TEM) and up-conversion emission spectrum of the steady-state test methods and other studies of rare-earth doped nanocrystals BaYF5 morphology, size and upconversion fluorescence properties.
　　By changing the precursor solution pH, EDTA and Y3 can control the ratio of the size of nanocrystals BaYF5, which experimental results discussed BaYF5 the crystallization process of nanocrystal nucleation rate controlling factor. Studied in detail the different http://www.chinamagnets.biz/ rare-earth ion-doped nanocrystals of BaYF5 spectral properties, especially the co-doped nanocrystals of BaYF5 red, green and blue upconversion light emission properties. Of BaYF5: Yb, Er; BaYF5: Yb, Tm; BaYF5: Yb, Ho; BaYF5: Nd, Yb, Er luminescence mechanism of the system for four kinds of detailed analysis. These results indicate that BaYF5 nanocrystals with high energy transfer efficiency, and given the small size of nanocrystalline BaYF5 there, look at other aspects of biological testing is widely used.
　　Degree Year: 2010