| LED(Light Emitting Diode)is a new kind of solid state lighting technology,with high photo synthetic efficiency,low energy consumption,long lifetime,pollution-free and other advantages have attracted more and more attention.It has been used in many fields,such as smart mobile phone screen and are expected to play an important role of automotive lighting.The currently LED implementation methods include organic LED,Quantum dot LED and phosphor converted LED that are widely used in daily life.Phosphor converted LED(PC-LED)is a main way to realize white light LED(WLED),the rare earth doped phosphor because of its potential application in lighting,display and white LED or other fields,which has become a hotspot in the study of light.We can control the kinds and the ratio of rare earth ions doped to obtain different colors of phosphor.At present,The approach of PC-LED to realize white ligh emission are mainly include blue LED chip with yellow phosphor,UV excitation LED chip with RGB phosphors,RGB LED chip mixed into white light.Among them,the blue LED chip with yellow phosphor is the way most widely used,but it still has a disadvantage of low efficiency,and its cooperate to get the white light is often due to a lack of red colour rendering index to get cold white light(CRI<75).In recent years,UV LED chip with RGB phosphor have an extensive research and made a positive progress,although its white light colour rendering index is better than the blue LED chip with phosphor,but still has the drawback of low efficiency and short lifetime.To resolve the proplem of prevalence low luminous efficiency of phosphors,searching a new method or find some new materials to overcome the shortcoming of phosphor is urgent.Tungstates and molybdates due to its worldwide in the near ultraviolet band and blue light range of M-O(M=W,Mo)charge transfer band optical absorption and Trivalent europrum(Eu3+)is often used as activator of red material,the characteristic emission peak at about 610-630 nm which belongs to narrow half peak width withbright luminous color,when Eu3+ doped into some molybdenum acid salt compounds will get good red emission,the emission of Eu3+ and tungstate materials will achieved good colour rendering index white light,it will be benefical to improve the white LED red color defects.On the other hand,in recent years the localized surface plasmon resonance(LSPR)effect of metal which is a kind of surface plasmon resonance(SPR)which is defined as an electromagnetic resonance phenomenon that occurs between the surface electrons of a metal and the surrounding dielectric materia are widely applied in the lighting materials and devices.The quantum efficiency of luminescent materials can be enhanced because of the existence of the LSPR effect due to its absorption of light and energy transfer.Thus,the LSPR effect provides a new idea for solving the low quantum efficiency of phosphors.In this dissertation,we prepared the Liln(WO4)2 phosphor by solid phase sintering synthesis method and optimized the ratio of Eu3+ doped into phosphor,in order to achieve the best white light emission of our sample.In addition,the LSPR effects of metal(Ag,Pt)act on the white light phosphor was investigated,Through the experiment we not only successfully prepared LiIn0.93(WO4)2:0.07Eu3+and LiIn0.93(WO4)2:0.07Eu3+/yM(M=Ag,Pt)and realized the phosphors have a good red color in white recombination when excited at 300 nm,but also due to the meatl(Ag,Pt)Loaded,using various kinds of analysis and characterization techniques confirmed the LSPR effect of metal acted the positive role to enhance the flourscence properties of the phosphor,the interaction mechanism between the LSPR effect of metal and LiIn0.93(WO4)2:0.07Eu3+phosphor makes a preliminary argument,the promoting effect on the properties of phosphor is compared between different metal(Ag,Pt).Through this study,we have confirmed the positive function of LSPR effect of metal on phosphor research,and it has profound application significance in practical productionof phosphor. |
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