Rare Earth Doped Of Sio <sub> 2 </ Sub> Gel Matrix, Preparation And Characterization Of Luminescent Materials

Using sol-gel process, pure SiO₂ xerogel , Tb³⁺doped , Tb³⁺ and Eu³⁺ co-doped SiO₂ substrate xerogel and film were prepared. The molecular config.uration of xerogel were characterized by using FT-IR spectra. appearance of film were carried out by means of Atomic Force microscope(AFM), the excitation and emission spectra were measured by spectrophotometer equipment.The luminescent feature of pure SiO₂ xerogel have been researched, which showed strong emission of ultraviolet and blue light. The ultraviolet emission was related to interface states, and blue emission was caused by defect states. The emission intensity was enhanced largely annealed at 800℃.The emission spectra of Tb³⁺ doped sample was consisted of 6 peaks under 250nm excitation, which located at 379nm, 414nm, 485nm, 545nm, 588nm, 622nm responded to ⁵D₃â†'⁷F₆, ⁵D₃â†'⁷F₄, ⁵D₄â†'⁷F_J (J=6,5,4,3) transition of Tb³⁺ ions respectively. Influence of annealing temperature, water content, boric acid on the luminescent characteristic have been studied, On the condition of annealing temperature was 700℃and of the mole ratio of TEOS:ETOH:H₂O was 1:4:5 and of acid concentration was 10%, the emission intensity of Tb³⁺ doped sample was improved.Influence of annealing temperature and Tb³⁺ concentration on the emission intensity of Eu³⁺ and Tb³⁺ co-doped samples have been researched, when the mass ratio of Eu³⁺ : Tb³⁺ is 5:1, and the annealing temperature is 700℃, It showed intense red emission ,however, with the same mass ratio of Eu³⁺ : Tb³⁺, it showed intense blue emission annealed at 850℃, the original idea of energy transfer from Tb to Eu in SiO₂ substrate have been discussed, and the blue emission intensity enhanced phenomena of Eu²⁺ ion , which have been illuminated .Tb³⁺ doped,Tb³⁺ and Eu³⁺ co-doped SiO₂ film with blue and green emission were prepared by dip-coating method. 0.3% Tb³⁺ doped sample showed strong green emission with 5 lays annealed at 750℃. 0.1%Tb³⁺ and 0.5%Eu³⁺ co-doped showed blue emission with 7 lays annealed at 700℃. with the result of AFM picture annealed at different temperature, Improvement of mechanism have been discussed about emission intensity of blue and green...