Synthesis Of Rare-Earth Ions Doped Low-dimensional Nanostructures And Investigation Of Their Luminescence Properties

Low-dimensional nanostructured materials have sparked a worldwide interest due to their unique electronic, optical, and mechanical properties and their potential applications in nanodevices and functional materials. It is known that structure, dimension, shape and size have important effect on the properties of low-dimensional nanomaterials. However, how the morphology of a nanostructure to determine its physical properties has been unknown until present days.As a micro structural probe a lanthanide ion can give us plentiful information about the local structure by spectroscopy. Therefore, the main aim in my thesis'job is to synthesize some RE ions doped nanostructures with special morphologies and to investigate their physical properties by RE spectra. In order to achieve this goal, we synthesized Yb³⁺/Er³⁺ co-doped cubic Y2O3 nanostructures and hexagonal lanthanum fluoride nanocrystals, Yb³⁺/Tm³⁺ co-doped yttrium fluoride and lanthanum fluoride nanoshees, Eu³⁺ doped barium fluorides and so on. Furthermore, their structural properties were investigated by using spectral methods, such as upconversion fluorescence, selective excitation, infra-red spectrum, and etc. More detailed items of the thesis work were list as below.1. Yb³⁺/Er³⁺ co-doped cubic Y₂O₃ nano-tubes, nano-particles and nano-flakes were synthesized by using a hydrothermal method. All the three nanostructures showed good ability in up-conversion emitting. The dependence of their fluorescence properties on morphologies was found in the FTIR and fluorescent decay measurements. The spectral changes from nanotubes to nanoflakes indicate that the OH^- group in them plays an important role in the effect on their spectral properties. OH^- ions with high vibration...