Tm ~ (3) / Yb ~ (3) co-doped calcium fluoride films and microspheres and optical properties of

Title: Tm ~ (3) / Yb ~ (3) co-doped calcium fluoride films and microspheres and optical properties of
Author: Jiang Tao
Degree-granting units: Jilin University
Key words: rare earth doped;; ultraviolet light;; conversion;; morphology
Summary:
In recent years, synthesis and structure to determine the shape of micro-nano size particles on the film or converted light-emitting materials has become a research hotspot. People can be infrared light into visible light, ultraviolet light and even convert inorganic materials on a lot of research work carried out, a variety of different synthetic and rare-earth-doped luminescent materials with specific morphology. As the fluoride material has a low phonon energy and a wide range of light wavelengths, making the non-radiative relaxation to reduce the likelihood of the process, upconversion efficiency is improved, therefore, become widely used fluoride conversion matrix one of the materials. At present, the preparation of efficient upconversion materials and upconversion mechanisms of its becoming a serious problem around this problem, this paper mainly carried out the following work:
(1) the use of sol-gel method with hydrothermal secondary growth under the conditions of preparation of the Yb ~ (3), Tm ~ (3) co-doped CaF2 film, get the surface of nano-size uniform thickness CaF_2: Yb ~ (3) / Tm ~ (3) film, its up-conversion emission spectra were measured, observed ultraviolet upconversion luminescence phenomenon.
(2) by hydrothermal method and were prepared by annealing a large number of nanoparticles composed of Tm ~ (3) / Yb ~ (3) co-doped CaF_2 micron particle conversion on the ball. Samples under 980 nm laser diode light glows bright blue and ultraviolet upconversion fluorescence. Experiment by changing the hydrothermal reaction conditions, adding a mineralizing agent and surface active agent prepared samples with different morphologies. We studied the formation mechanism of the product that the nucleation process of the sample in line with Oswald ripening process, while, on the observed UV up-conversion emission phenomena are discussed.
Degree Year: 2010