本文選題：白光LED(發(fā)光二極管)　切入點：熒光粉　出處：《合肥工業(yè)大學(xué)》2015年碩士論文

【摘要】：白光LED(發(fā)光二極管,Light emitting diode)燈作為第四代綠色光源以其高效、節(jié)能、環(huán)保、低成本等優(yōu)點在現(xiàn)代社會己部分取代傳統(tǒng)照明光源,全部取代指日可待,其性能與人們生活息息相關(guān)。與黃、綠色熒光材料相比,紅色熒光材料還有待于進(jìn)一步研究。由于良好的熱穩(wěn)定性和化學(xué)穩(wěn)定性,寬的激發(fā)和發(fā)射光譜帶,氮化物Sr2Si5N8:Eu2+紅色熒光粉引起了廣泛關(guān)注。但是嚴(yán)格的合成條件、高昂的成本限制了其在白光LED中的應(yīng)用。為此,論文探索了以金屬氧化物為原料的LED氮化物紅色熒光粉Sr2Si5N8:Eu2+;盈和條件合成方法,通過采用田口優(yōu)化設(shè)計與酒精濕磨的高能球磨工藝,對SrCO3與Si3N4展開單獨球磨以及對SrCO3和Si3N4共同球磨的混料方式,藉助紅外光譜、x射線衍射與熒光光譜對球磨中間產(chǎn)物和高溫固相反應(yīng)終端產(chǎn)物的化學(xué)鍵、晶體結(jié)構(gòu)與熒光光譜分析表明,球磨過程中Si-N鍵的破損以及Si3N4原料中氧含量偏高是LED氮化物紅色熒光粉Sr2Si5N8:Eu2+合成過程中產(chǎn)生雜相的主要原因。對此,我們采用保護(hù)Si3N4原料中Si-N鍵的完整性,對SrCO3單獨球磨的工藝措施成功探索出利用SrCO3原料合成高純Sr2Si5N8:Eu2+;定光粉的新工藝。論文在研究了單質(zhì)復(fù)色熒光粉Li2SrSi04:Eu2+,Ce3+扣Eu2+與Ce3+之間能量關(guān)系的基礎(chǔ)上發(fā)現(xiàn)現(xiàn)有的Li2SrSi04晶體結(jié)構(gòu)(ICSD167334)認(rèn)為的Li2SrSi04具有三方結(jié)構(gòu)(空間群p3121(152)),其中Sr只有一種格位,不能很好地解釋實驗測得的Li2SrSi04:Eu2+,Ce3+的激發(fā)和發(fā)射光譜。論文采用XRD、熒光光譜、高分辨透射電子顯微鏡、脈沖納秒光學(xué)參量振蕩器等分析方法,結(jié)合GSAS晶體結(jié)構(gòu)精修軟件,解出了一種新的Li2SrSi04晶體結(jié)構(gòu),為單斜晶系,空間群為C121,其中Sr存在兩種格位。針對深紫外LED應(yīng)用, 論文研究了YBO3基質(zhì)中發(fā)光中心Bi3+和Sb3+離子與Eu3+離子之間的能量傳遞關(guān)系,研究結(jié)果表明,Bi3+能夠把激發(fā)能有效傳遞給Eu3+,但是與Bi3+具有相同ns2電子構(gòu)型的Sb3+由于激發(fā)和發(fā)射帶之間大的斯托克斯位移,導(dǎo)致Sb3+離子的發(fā)射帶與Eu3+的激發(fā)帶不匹配,不能將激發(fā)能有效傳遞給Eu3+。
[Abstract]:As the fourth generation green light source, the white LED (Light emitting Diode) light source has partially replaced the traditional lighting source in modern society, all of which will be replaced by the near future with its advantages of high efficiency, energy saving, environmental protection and low cost. Its properties are closely related to people's lives. Compared with yellow and green fluorescent materials, red fluorescent materials need to be further studied. Due to their good thermal and chemical stability, wide excitation and emission spectra, The application of nitride Sr2Si5N8:Eu2 red phosphors in white LED is limited by the strict synthesis conditions and high cost. Therefore, the paper explores the Sr2Si5N8:Eu2 nitride red phosphors using metal oxides as raw materials. By using Taguchi optimization design and alcohol wet milling technology, the mixing method of SrCO3 and Si3N4 and SrCO3 and Si3N4 are developed. The chemical bonds, crystal structure and fluorescence spectra of the intermediate products of ball milling and the end products of high temperature solid state reaction were analyzed by means of X-ray diffraction and fluorescence spectra. The damage of Si-N bond during ball milling and the high oxygen content in Si3N4 raw material are the main reasons for the formation of heterogenous phase in the synthesis of LED nitride red phosphor Sr2Si5N8:Eu2. Therefore, we protect the integrity of Si-N bond in Si3N4 raw material. The preparation of high purity Sr2Si5N8:Eu2 by using SrCO3 raw material was successfully explored in the process of single ball milling of SrCO3. Based on the study of the energy relationship between Eu2 and Ce3, it is found that the existing Li2SrSi04 crystal structure (ICSD167334) shows that the Li2SrSi04 has a tripartite structure (space group p3121t152n), in which Sr has only one lattice. The excitation and emission spectra of Li2SrSi04:Eu2 Ce3 measured by experiment can not be explained well. In this paper, XRD, fluorescence spectrum, high resolution transmission electron microscope, pulse nanosecond optical parametric oscillator and GSAS crystal structure refinement software are used. A new Li2SrSi04 crystal structure, which is monoclinic and space group C121, is obtained. For the application of deep ultraviolet LED, the energy transfer relationship between Bi3 and Sb3 ions and Eu3 ions in YBO3 matrix is studied. The results show that Bi3 can effectively transfer the excitation energy to Eu3, but Sb3 with the same ns2 electron configuration as Bi3 has a large Stokes shift between the excitation and emission bands, which leads to the mismatch between the Sb3 emission band and the Eu3 excitation band. The excitation energy can not be effectively transferred to Eu3.
【學(xué)位授予單位】：合肥工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN312.8

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本文編號：1680528