Investigation On Dual-frequency Up-conversion Property Of Erbium Doped NaYF₄ Nanocrystal And Tellurate Glass

With the development of the display technology, the demand for 3-D display technology is increasingly required. Scientists want to get breakthrough in this field to improve the quality of the 3-D image. The image in television was accomplished by using quick scan of the electron beam method of forming an image on a two-dimensional plane before the liquid crystal display appeared. True 3-D display can be achieved if the scanning occurs in three-dimensional space in the same manner as TV. A transparent luminescent material in which every point can be precisely controlled independently is required for the technology. By the method of a quick scan of the inside light emitting point regularly arranged in the material, three-dimensional image can be formed, thus true three-dimensional display is achieved.Dual-conversion luminescent material can meet this requirement. Up-conversion can be induced when simultaneously stimulated by two laser beams with different wavelengths. This luminescence only occurs exactly at the point where two laser beams meets, thus it enable control of single point luminescence which meets threedimensional display’s material requirementsIn this article hexagonal NaYF4 doped with Er3+ was prepared through solvent-thermal method and its morphology, structure and other basic physical properties are characterized. As the key content of the paper, we study the up-conversion luminescence properties of the material. We analyze the fluorescence peak position of the erbium doped samples, luminous intensity and other basic information by measuring the fluorescence spectrum of dual excitation. The mechanism of fluorescence phenomenon is studied by measuring the power spectrum of erbium ion material and analyzing it with energy level structure. As a base material of true three-dimensional display, the effects of erbium ion doping concentration and the excitation intensity on the display contrast is investigated.In contrast, erbium doped telluride glass is prepared by the traditional method of solid-phase sintering. The sample’s fluorescence spectra and power spectral is measured, its conversion mechanism is also analyzed. Dual-frequency up-conversion quality of material is tested under different experimental conditions which visual display the influence of the experimental conditions on the display contrast. To further understand the spectroscopic properties of erbium-doped telluride glass absorption spectra of the samples, spectra of the samples are measured and its J-O coefficient is calculated. And then the Einstein spontaneous emission coefficient, branching ratio, fluorescence lifetime, emission sectional and other physical quantities of the material are calculated. The guiding role of the theoretical value we calculated played in the field of the three-dimensional display experiments is also analyzed.