Research Of Synthesis And Properties Of Silicon-oxynitride Phosphors

White light-emitting diodes(LEDs) are eco-friendly next generation light sources with fewer CO2gas emissions and energy consumptions less than that of conventional light sources. Rare earth doped oxynitride phosphors have been considered as promising phosphors for application to white LEDs because of high quantum efficiency and low thermal quenching of luminescence.This paper includes five chapters.Chapter Ⅰ is concern about the principle of light, the development of white light LEDs, the principle and structure of white light LEDs, the species of silicon oxynitride phosphors and commonly used preparation methods. Based on these theories, we put forward the purpose of this paper.In Chapter Ⅱ the experimental process of this work is described, including the starting materials, synthesis equipment, the synthesis process, material testing techniques.In chapter Ⅲ, yellow-emitting a-SiAlON:Eu2+phosphors were synthesized by a direct silicon nitridation and gas-reduction method. The effects of chemical composition, activator concentration and reaction parameters including starting materials, soaking temperature and post-processing on the composition and photoluminescence of the prepared powders have been studied. In the end, we discussed the possibile mechanisms of the one step direct silicon nitridation and gas-reduction method.In chapter4, another excellent oxynitride phosphor, red emitting Sr2SisNg:Eu2+phosphor was synthesized by a direct silicon nitridation and gas-reduction method. The effects of synthesis parameters, including soaking temperature, gas species and flow rate on the composition and photoluminescence of the prepared powders have been studied.Finally, chapter5makes a conclusion of the direct silicon nitridation and gas-reduction method as well as the properties of phosphors synthesized by this method. We also brought forward some derections to this method.