Preparation And Luminescent Characteristics Of Silicon-nitrogen Based Phosphor For White LED

Energy crisis and environmental pollution are two major challenges that the human face,they are also the major task that must be given priority to the implementation of sustainabledevelopment strategy in China. The way to solve the global energy shortage is the strategy ofdeveloping energy efficient technologies, green environmental protection. White light emittingdiode (white Light Emitting Diode, referred to as WLED) is a new type of solid state lighting,compared with the traditional lighting source, white LED attracts widely attention because of theadvantages of high efficiency, energy saving, environmental protection, green lighting, long-lifeadvantages, therefore in the "sustainable development" background, it has been expected in thefourth generation of lighting source.Nowadays, methods to obtain white light are mainly through the LED chips and thephosphors. Therefore, as an important part of the white light LED, phosphor performance directlyaffects the white LED luminous efficiency, color temperature, color rendering index, light and life.The study shows that, rare earth doped silicon nitrogen compounds fluorescent powder has manyexcellent properties because of special crystal structure,, such as good stability, emittingwavelength tunable, near ultraviolet or blue light LED chip excitation, temperature quenchingeffect is weak, with which it has been the most application value of a new type of white LEDphosphors. This thesis chooses the MSi22O2N2:Eu+(M=Ca, Sr, Ba)and Ba3Si6O9N4:RE1, RE2(RE1, RE2=Eu2+, Mn2+, Mg2+, Ce3+, Dy3+, Er3+, Yb3+, Tb3+) phosphor powder as the researchobject, it gives a detailed study of the high temperature solid phase method and analysis of theluminescence characteristics. At the same time the thesis uses two-step to obtain Ba3Si6O9N4phosphors and analysis the similarities and differences between two-step to obtain Ba3Si6O9N4phosphors and high temperature solid phase synthesis.1. MSi2+2O2N2: Eu(M=Ca, Sr, Ba) phosphors were prepared by high temperature solid-statemethod. System research the MSi2O2N2: Eu2+(M=Ca, Sr, Ba) phosphors luminescence propertieswith different synthesis temperature and Eu2+-doping concentration. The emission spectrum ofMSi2O2N2: Eu2+(M=Ca, Sr, Ba) phosphors show the obvious red shift phenomenon as a function of Eu2+content, also, as the increase of M2+ionic radius（Ca2+＜Sr2+＜Ba2+）, the emissionspectrum show the obvious blue shift phenomenon.2. Ba3Si6O9N4: RE1,RE2（RE1, RE2=Eu2+、Mn2+、Mg2+、Ce3+、Dy3+、Er3+、Yb3+、Tb3+）phosphors were prepared by high temperature solid-state method. And theluminescence properties were studied. According to the theory of doping, the effect of activatoron the luminescence behavior of Eu2+activated Ba3Si6O9N4phosphors were discussed in detail.Then, the critical distance between Eu2+and Ce3+suggest that the energy transfer mechanism inBa3Si6O9N4phosphors is due to dipole-dipole interactions.3. Ba3Si6O9N4: Eu2+phosphors were prepared by two-step method, and studied the effecton luminescence properties. The result shows that emission spectrum have obvious blue shiftphenomenon by two-step method, then use energy dispersive spectroscopy (EDS) explain thereason for this.