NaYF_4: Er ~ (3) / Yb ~ (3) enhanced upconversion luminescence and spectral design

Title: NaYF_4: Er ~ (3) / Yb ~ (3) enhanced upconversion luminescence and spectral design
Author: Wu Li
Degree-granting unit: Harbin Institute of Technology
Keywords: fluoride;; Er ~ (3) ion;; luminescence enhancement;; nanorods;; spectrum regulation
Summary:


Light rare-earth doped nanocrystals in solar cells, biomarkers, light-emitting devices, laser anti-counterfeiting and other areas has broad application prospects. The low-conversion luminescence efficiency is to limit its practical application of the main factors. Magnetic lifter Upconversion luminescence intensity increased exploration methods, not only has important theoretical research value, but also has important practical significance. NaYF_4: Er ~ (3) / Yb ~ (3) a combination of nano-crystalline because of its strong and rich luminous intensity and fluorescence spectra of wide public concern. Papers mainly focus on "NaYF_4: Er ~ (3) / Yb ~ (3) enhanced upconversion luminescence and spectral design" to carry out family research.


Oil were prepared using different sizes of hot-cubic phase and hexagonal phase of NaYF_4: Er ~ (3) / Yb ~ (3) nanoparticles and nanocrystalline columnar. By changing the reaction time, reaction temperature and adjust the ratio of rare earth ions NH4F/NaF and develop a better preparation of upconversion fluorescence properties of hexagonal columnar nanocrystalline NaYF_4 new method. By infrared absorption spectra and fluorescence spectra of the probe, to clarify the enhancement mechanism of upconversion.


Have explored the use of columnar nanocrystals synthesis, synthesis batch NaYF_4: Er ~ (3) / Yb ~ (3) nanorods change the sensitizer Yb ~ (3) concentration, while maintaining the nanocrystal shape and crystal lattice structure remains unchanged, successfully introduced a way to improve upconversion luminescence intensity and spectral adjustment http://www.999magnet.com/products/131-magnetic-lifter method for the acquisition of monochrome red light indicates a new direction, and fluoride proved Er ~ (3) and Yb ~ (3) ions in the presence of reverse energy transfer process.


In NaYF_4: Er_ (0.02) ~ (3) / Yb_ (0.2) ~ (3) of the rare earth materials, the introduction of the new-doped ion - Ce ~ (3) ion, the use of Ce ~ (3) and Er ions ~ (3) ion energy levels match the special relationship between the cross-relaxation through the level, successfully Er ~ (3) up-conversion fluorescence spectra of regulation, a single green upconversion provides access to a new idea .
Degree Year: 2010