本文關(guān)鍵詞： 硼酸鹽 熒光粉 白光LED 發(fā)光性能 稀土摻雜　出處：《陜西科技大學》2017年碩士論文　論文類型：學位論文

【摘要】：白光LED作為新一代照明和顯示光源,具備綠色環(huán)保、效率高、使用時間長的優(yōu)點。使用近紫外芯片與三基色熒光粉配合獲得白光是生產(chǎn)白光LED的主流方法之一。隨著研究和應(yīng)用的擴展,人們對白光LED的發(fā)光性要求越來越高,然而如今該領(lǐng)域存在缺少高效紅色熒光粉導致白光LED普遍顯色差,色溫高,以及能夠與近紫外芯片良好匹配的紅色綠色熒光粉種類較少的問題。因此,開發(fā)高效穩(wěn)定的近紫外激發(fā)三基色熒光粉是LED領(lǐng)域的研究重點。硼酸鹽具有合成溫度低,結(jié)構(gòu)穩(wěn)定的特點,是性能優(yōu)良的熒光粉基體。本文使用高溫固相法對Na_3Gd_2(BO_3)_3和Y_2Ba_3B_4O_(12)兩種硼酸鹽系列的稀土熒光粉進行了合成,研究了不同摻雜離子及不同摻雜濃度熒光粉的晶體結(jié)構(gòu)、微觀形貌以及發(fā)光性能,并分析了熒光粉的發(fā)光機理。實驗首先制備了不同煅燒溫度和保溫時長的Na_3Gd_(2-x)(BO_3)_3:xEu~(3+)熒光粉。各測試結(jié)果表明,當樣品在800oC下煅燒,保溫時間是5h時,其析晶情況最佳,發(fā)光最強。據(jù)此工藝參數(shù)合成了不同摻雜量的Na_3Gd_(2-x)(BO_3)_3:x Eu~(3+)熒光粉,樣品均在350~400nm范圍內(nèi)有較強的激發(fā)峰,最強峰位于394nm處;發(fā)射光譜顯示樣品在592nm和614nm有兩個主要發(fā)射峰,并以波長614nm的峰為主。當Eu~(3+)摻量為x=0.3,熒光粉的發(fā)射光最強,此時熒光粉的CIE色坐標為(0.650,0.350),與NTSC標準紅光色坐標非常接近。利用多種離子共摻實現(xiàn)單一基質(zhì)熒光粉的多色發(fā)射成為頗受關(guān)注的研究課題,在此背景下,利用Tb~(3+)和Eu~(3+)共摻,制備了能夠被紫外和近紫外光有效激發(fā)的Na_3Gd_(2-x)-y(BO_3)_3:xTb~(3+),yEu~(3+)熒光粉。在368nm激發(fā)光下,其發(fā)射光譜中同時出現(xiàn)Tb~(3+)和Eu~(3+)的典型發(fā)射峰。當Eu~(3+)摻雜量漸漸增多,Tb~(3+)和Eu~(3+)之間通過電偶極-電偶極相互作用發(fā)生了能量傳遞,Tb~(3+)的特征發(fā)射逐漸減弱而Eu~(3+)的逐漸加強,熒光粉的色坐標出現(xiàn)綠色→黃色→橙色的漸變,實現(xiàn)了發(fā)光顏色的調(diào)節(jié)。此外,以Dy~(3+)摻雜制備Na_3Gd_(2-x)(BO_3)_3:xDy~(3+)單基質(zhì)白光熒光粉。在353nm波長激發(fā)下,樣品產(chǎn)生白光,主要發(fā)射光波長為479nm和574nm,且波長為574nm的黃光發(fā)射強度大于479nm的藍光發(fā)射,熒光粉的色坐標也因此位于白光區(qū)域中偏黃光的位置。利用高溫固相法進行制備,研究得到Y(jié)_2Ba_3B_4O_(12)基熒光粉最佳的工藝參數(shù)如下:預(yù)燒溫度400oC,煅燒溫度1150oC,保溫時長3h。該工藝制度獲得的樣品經(jīng)檢測為純相Y_2Ba_3B_4O_(12),析晶度高,微觀下晶粒表面光滑,發(fā)光性能最好。利用該最佳工藝參數(shù)制備Y_(2-x)Ba_3B_4O_(12):xDy~(3+)熒光粉,樣品在350~400nm波段內(nèi)有明顯激發(fā)峰,主要發(fā)射峰波長為480nm和575nm,在近紫外激發(fā)下呈白光發(fā)射。該熒光粉中Dy~(3+)的最佳摻雜量x=0.20,此時的色坐標為(0.386,0.412),與理想白光相比,Y_(2-x)Ba_3B_4O_(12):xDy~(3+)熒光粉發(fā)射光的色溫有明顯的降低。此外,實驗利用Sm~(3+)摻雜制備了橙紅色熒光粉Y_(2-x)Ba_3B_4O_(12):xSm~(3+)。該系列樣品能夠在紫外和近紫外光下被激發(fā),主要激發(fā)峰的波長是403nm,主要發(fā)射峰分別位于562nm,602nm和647nm。Y_(2-x)Ba_3B_4O_(12):xSm~(3+)熒光粉的猝滅濃度為x=0.15,出現(xiàn)濃度猝滅的原因是能量在鄰近的Sm~(3+)間以電偶極-電偶極作用方式的傳遞。熒光粉Y_(2-x)Ba_3B_4O_(12):xSm~(3+)的CIE坐標位于橙紅色區(qū),具有一定的開發(fā)應(yīng)用潛能。
[Abstract]:As a new generation of white LED lighting and display light source, with green environmental protection, high efficiency, the advantages of long time use. Using near UV chip and phosphor for white light with three is one of the main production methods of white LED. With the expansion of research and application, people on the white LED light of increasingly high demand now, however, the existing lack of efficient red phosphor in general show white LED color, high color temperature, red green fluorescent powder and less species with near UV chip good matching problem. Therefore, the development of highly efficient and stable near ultraviolet excitation of three color phosphor is the focus of LED research field. With the synthesis of borate the characteristics of low temperature, stable structure, is the phosphor substrate with excellent properties. In this paper, using high temperature solid phase method of Na_3Gd_2 (BO_3) _3 and Y_2Ba_3B_4O_ (12) of two kinds of rare earth borate series of fluorescent powder The synthesis and crystal structure of different doped ions and different doping concentration of fluorescent powder, microstructure and luminescence properties of the phosphor luminescence mechanism and experimental analysis. Firstly, Na_3Gd_ different calcination temperature and holding time to prepare (2-x) (BO_3) _3:xEu~ (3+) phosphor. The test results show that when the samples at 800oC, calcination, holding time is 5h, the crystallization of the best, the most luminous. Different doped Na_3Gd_ was synthesized according to the process parameters (2-x) (BO_3) _3:x Eu~ (3+) phosphor samples have strong excitation peaks in the range of 350~400nm, the strongest peak is located at 394nm emission spectra of the sample; there are two main emission peaks at 592nm and 614nm, and the peak wavelength of 614nm. When Eu~ (3+) content was x=0.3, the strongest emission phosphors, the CIE chromaticity coordinates for (0.650,0.350), and NTSC standard red color coordinate is very close. 鍒╃敤澶氱紱誨瓙鍏辨幒瀹炵幇鍗曚竴鍩鴻川鑽у厜綺夌殑澶氳壊鍙戝皠鎴愪負棰囧彈鍏蟲敞鐨勭爺絀惰棰，

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