發(fā)布時間：2018-04-13 17:06

  本文選題：白光LED + 高溫固相法　； 參考：《大連海事大學》2017年碩士論文

【摘要】：白光LED具有節(jié)能、環(huán)保、高效等優(yōu)點,被譽為第四代照明光源�，F(xiàn)階段商用的白光LED是由藍光LED芯片與黃光熒光粉組合而成的,這種缺失紅光成分的白光,相對來說顯色指數(shù)并不理想。故本文主要探究的方向在于:(1)研究發(fā)光性能良好的紅光熒光粉;(2)研究能被近紫外激發(fā)的單一相白光熒光粉。本文采用的制備熒光粉的方法主要是高溫固相法,通過高溫固相法制備了一系列不同摻雜濃度的紅光熒光粉Ba_3Gd(PO_4)_3:Eu~(3+)和GdNbO_4:Sm~(3+),以及白光熒光粉GdNbO_4:Dy~(3+)樣品。并探究了各樣品的光學性質(zhì)和色度學性質(zhì),主要內(nèi)容包括:(1)通過XRD衍射圖譜分析了Ba_3Gd(PO_4)_3:Eu~(3+)樣品的晶體結(jié)構(gòu)。利用Van Uitert模型對~5D_0能級熒光的濃度猝滅行為進行了研究,發(fā)現(xiàn)濃度猝滅是由于Eu~(3+)與Eu~(3+)間交換相互作用所導致。分析了~5D_0能級熒光發(fā)射對溫度的依賴關(guān)系,給出了溫度猝滅行為符合crossover模型的結(jié)論。利用Eu~(3+)的發(fā)射光譜和熒光衰減數(shù)據(jù),計算了~5D_0→~7F_J輻射躍遷速率及熒光分支比,同時得到了光學躍遷強度參數(shù)。(2)GdNbO_4:Sm~(3+)樣品的XRD測試結(jié)果表明該樣品為純相,Sm~(3+)的摻雜并沒有改變樣品的晶體結(jié)構(gòu)。隨著Sm~(3+)摻雜濃度的增加,樣品發(fā)生了濃度猝滅。用Van Uitert模型對樣品進行擬合,推斷引起樣品濃度猝滅的機制是電偶極-電偶極相互作用,最后對不同摻雜濃度的樣品進行了色坐標計算。(3)測試了GdNbO_4:Dy~(3+)樣品的XRD衍射圖譜,結(jié)果表明該樣品為純相,Dy~(3+)發(fā)光中心的摻雜并沒有對GdNbO_4的晶體結(jié)構(gòu)造成影響。用Van Uitert模型對樣品在不同摻雜濃度條件下的發(fā)射強度進行積分擬合計算,了解到引起樣品濃度猝滅的機制是電偶極-電偶極相互作用。對摻雜不同濃度的樣品計算了黃藍比以及色坐標,并且計算了樣品色坐標隨著溫度提高的變化規(guī)律,發(fā)現(xiàn)樣品在不同溫度下仍然有著良好的發(fā)光性能。
[Abstract]:White LED, with the advantages of energy saving, environmental protection and high efficiency, is praised as the fourth generation lighting source.At present, the commercial white LED is composed of blue LED chip and yellow phosphor.Therefore, the main research direction of this paper is: (1) to study the red phosphor with good luminescence performance.) to study the single phase white phosphor which can be excited by near ultraviolet.In this paper, a series of red phosphor (Ba_3Gd(PO_4)_3:Eu~(3) and white phosphor (GdNbO_4:Dy~(3) with different doping concentration were prepared by high temperature solid state method.The optical and chromaticity properties of the samples were investigated. The main contents include: 1) the crystal structure of Ba_3Gd(PO_4)_3:Eu~(3) samples was analyzed by XRD diffraction pattern.The concentration quenching behavior of 5D0 level fluorescence was studied by using Van Uitert model. It was found that the concentration quenching was caused by the exchange interaction between Eu~(3) and Eu~(3).The dependence of 5D0 energy level fluorescence emission on temperature is analyzed, and the conclusion that the temperature quenching behavior accords with the crossover model is given.Based on the emission spectrum and fluorescence attenuation data of Eu~(3, the radiation transition rate and the fluorescence branch ratio of 5D\\ +\\\At the same time, the XRD test results of the optical transition intensity parameter... GdNbOS 4: Sm3) show that the doping of the sample is pure phase, and the crystal structure of the sample has not been changed.With the increase of doping concentration of Sm~(3, the concentration quenching occurred.The Van Uitert model was used to fit the samples. It was inferred that the mechanism of concentration quenching was electric dipole-electric dipole interaction. Finally, the XRD diffraction patterns of samples with different doping concentrations were measured by color coordinate calculation.The results show that the doping of the pure phase Dy Dy + 3) has no effect on the crystal structure of GdNbO_4.The Van Uitert model was used to calculate the emission intensity of the samples with different doping concentrations. It was found that the mechanism of concentration quenching was electric dipole dipole interaction.The yellow-blue ratio and the color coordinates of the samples with different doping concentrations were calculated. The variation of the color coordinates with the increase of temperature was calculated. It was found that the samples still had good luminescence properties at different temperatures.
【學位授予單位】：大連海事大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O482.31;TN312.8

【參考文獻】

相關(guān)期刊論文 前10條

1 林嘯;馮昂;張志軍;趙景泰;;VUV spectroscopic properties of rare-earth(RE=Eu,Tb and Dy)-doped A_2Zr(PO_4)_2(A=Li,Na and K) phosphates[J];Journal of Rare Earths;2014年10期

2 鐘劍明;趙韋人;藍立財;王建青;;Hydrothermal synthesis and luminescence properties of Eu~(3+) and Sm~(3+) codoped BiPO_4[J];Journal of Rare Earths;2014年01期

3 董國義;侯春彩;楊志平;劉鵬飛;董宏巖;梁小雙;;新型紅色熒光粉Ca_(0.5)Sr_(0.5)MoO_4:Sm~(3+)的制備及光學性能[J];光電子.激光;2014年01期

4 王醒東;林中山;張立永;夏芳敏;孔梅梅;;掃描電子顯微鏡的結(jié)構(gòu)及對樣品的制備[J];廣州化工;2012年19期

5 楊志平;韓月;宋延春;趙青;周東站;劉玉峰;;紅色熒光粉Ba_(2 x)B_2O_5:xSm~(3+)的制備及發(fā)光性能[J];硅酸鹽學報;2012年03期

6 楊志平;馬欣;趙盼盼;宋兆豐;;SrAl_2B_2O_7:Dy~(3+)材料的制備及其發(fā)光性能[J];物理學報;2010年08期

7 花景田;陳寶玖;孫佳石;程麗紅;仲海洋;;稀土摻雜材料的上轉(zhuǎn)換發(fā)光[J];中國光學與應用光學;2010年04期

8 薛艷娜;肖芬;張勤遠;姜中宏;;Synthesis and luminescent properties of polycrystalline Gd_2(MoO_4)_3:Dy~(3+) for white light-emitting diodes[J];Journal of Rare Earths;2009年05期

9 康明;劉軍;孫蓉;;CaCO_3基紅色熒光粉的合成及其光譜性能分析[J];人工晶體學報;2009年03期

10 劉國聰;陳立妙;段學臣;梁達文;;Synthesis and characterization of Sm~(3+)-doped CeO_2 powders[J];Transactions of Nonferrous Metals Society of China;2008年04期

相關(guān)碩士學位論文 前3條

1 田碧凝;稀土摻雜鋅酸釓鋇光轉(zhuǎn)換熒光粉的光譜性質(zhì)及發(fā)光機理研究[D];大連海事大學;2013年

2 劉彥梅;鐿鉺雙摻鎢酸鉛晶體發(fā)光性能的研究[D];哈爾濱工業(yè)大學;2009年

3 韋小艷;LED用稀土激活堿土硅酸鹽白光熒光粉的研究[D];長春理工大學;2009年

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本文編號：1745414