TB ^{3 +} Doped Sio ₂ Core - Shell Structure Study On Preparation And Luminescent Properties Of Materials

We prepared different structures of SiO2:Tb3+@SiO2 and SiO2@SiO2:Tb3+ core-shell luminescence materials by Sol-Gel method, and prepared SiO2:Tb3+ fluorescent microspheres by using improved StOber method in this paper. The influence of various factors on characteristics of luminescence were studied through the characterization tests of PL spectra, TEM, SEM and EDS spectrum. The experimental results that we obtained were analyzed and the possible mechanism were discussed to provide experimental basis and theoretical ideas for the study of light emitting reinforcement.The influence factors of fluorescent, such as core-shell ratio, core-shell combine craft, centrifugal processing of sample SiO2:Tb3+@Si02 was studied. Samples that prepared by Sol-Gel method obtained the largest luminous intensity and stronger than SiO2:Tb3+powder when core-shell ratio was 1.2g/25ml and preparation technology was first ageing shell layer solution then coating. Fluorescence attenuation life was tested that probably increased 3.4% than SiO2:Tb3+ powder prepared by Sol-Gel method. The luminous property of supernatant fluid that we obtained after centrifugal stronger than the lower precipitation no matter how much nuclear quality or how style of structure, but the Tb3+fixed ability of ch craft on the core was powerful than zj craft while contrasted the luminous intensity of the precipitation prepeared by two crafts.We prepared SiO2@SiO2:Tb3+ core-shell luminescence materials by using Sol-Gel and stOber methods respectively. For the samples of SiO2@SiO2:Tb3+ by using Sol-Gel method, we abtained the largest luminous intensity and stronger than SiO2:Tb3+ powder when core-shell ratio was 1.2g/25ml, preparation technology was first coating then ageing shell layer solution and temperature was increased 600℃heat preservation firstly 750℃later. Due to the influence of material growth mode, the luminous intensity of samples used ch craft was different from zj craft. While for the samples prepeared by StOber method, the largest luminous intensity was obtained when core-shell ratio was 0.2g/20ml. Ultrasonic processing made luminous ion on SiO2@SiO2:Tb3+ particle surface gathering crowds to a space to lead to concentration quenching. Hydrothermal removed the original Tb3+ that gathered around the partical surface to increase the intensity in the style of spreading, didn't so high concentration as to make emission missing. Centrifugal processing will lead luminous icon of the samples SiO2@SiO2:Tb3+to distribut uneven and weake the intensity with two preparation methods. Because the need of shell solution for per-unit nuclear material is less, the SiO2@SiO2:Tb3+ core-shell structural luminescence materials with StOber method have the advantage of high efficiency and energy saving.Considered the influence of doping concentration, heat treatment and other factors on fluorescence properties of SiO2:Tb3+microspheres with improved StOber method. When concentration was 4.86% and heat treatment was preservation at 300℃firstly then heat up to 850℃later, the samples obtained the biggest fluorescence intensity, more than the SiO2:Tb3+ powder that catalyze by hydrochloric acid. Compared to the SiO2:Tb3+powder, its interior quantum efficiency improved 94.29% and quantum efficiency improved 95.24%. SiO2:Tb3+ microspheres that inspired by uv-lamp displayed the green fluorescence emission in the dark condition. Meanwhile, this experiment also existed deficiency of large quantities of rare earth dopping, so remains to be for further research.