Sol-gel Combustion Method Synthesis And Luminescent Properties Of Aluminate Phosphor For White-LED

As a new type of solid-state light source,LEDs?light emitting diode,LED?show the great application prospect in the aspects such as indoor lighting,LCD display and the back light with its attractive advantages of energy consumption saving,high-efficiency,environmental,lifetime long-lasting and small volume aspects.Roughly,the three kinds of access to get the white LED is: light conversion technology,the multi-chip direct combination light conversion and multiple quantum well.So far,light conversion technology is more commonly used.However,the traditional YAG: Ce³⁺ phosphor is difficult to meet the demand of development due to low color rendering,high temperature and so on,and the near ultraviolet chip LED with tricolor phosphors of the combination is an effective way.Therefore,it is a great significance to make novel,stable and efficient development of LED phosphors for WLED technology.Presently,the main methods to prepare phosphors is high temperature solid-state method,but this method has shortages of long production period,high-temperature long-time calcinations and agglomeration,thus,it is needed to develop new techniques to prepare phosphors powders.Liquid are introduced in these methods to make sure that each ingredient can accurately be controlled and mixed.The combustion synthesis has the characteristics of simpleness,shortcut,and it is widely used in the synthesis of various oxides.The technology of reaction is that the redox reaction between metal nitrate and fuel in low temperature gives off heat to make synthetic reaction.Furthermore,the combustion process is facile,safe,instantaneous energy saving,and the product has high crystallinity and uniform particle size distribution.Accordingly,it is necessary to research the combustion synthesis for the development of white LED.The high quantum efficiency,thermal stability and chemical stability of the aluminate phosphor stimulated the research enthusiasm.In this paper,the aluminate fluorescent powder are prepared by low temperature combustion method and the structure and the luminescent performance characterization of system analysis,research methods and conclusions are as follows.First of all,the MMgAl₁₀O₁₇:Eu²⁺,MMgAl₁₀O₁₇:Eu²⁺,Er³⁺ and MMgAl₁₀O₁₇:Eu²⁺,Mn²⁺?M=Ca,Sr,Ba?phosphors were synthesized by combustion synthesis method,and the structure morphology and fluorescence properties were studied.It shows that we can obtain pure crystalline products by combustion synthesis.Secondly,we have doped Er³⁺ in the MMgAl₁₀O₁₇: Eu²⁺ to synthesize MMgAl₁₀O₁₇:Eu²⁺ in order to enhance the emission of MMgAl₁₀O₁₇: Eu²⁺.The obtained samples were characterized analysis,and it can explain excellently the concentration quenching and the sensitization effect of Eu²⁺.Thirdly,we have synthesized MMgAl₁₀O₁₇:Eu²⁺,Mn²⁺?M= Ca,Sr,Ba?phosphors to expand the scope of phosphor emission spectrum by the same method.Then the structure morphology and fluorescence properties were studied,and the theory of energy transfer was discussed deeply based on existing mechanism.Lastly,it can explain excellently the reason of phosphor luminescence affected by the ratio of Mn²⁺ ions.In this paper,a new method of low temperature combustion method are provided for the preparation of phosphors,and the luminescence properties of phosphor are raised by the process optimization.and then we prepared the high brightness phosphor of SrMgAl₁₀O₁₇:Eu²⁺,Er³⁺ and the color-tunable phosphor of SrMgAl₁₀O₁₇:Eu²⁺,Mn²⁺.