本文選題：有機電致發(fā)光　切入點：開殼分子　出處：《吉林大學》2017年碩士論文　論文類型：學位論文

【摘要】：在有機電致發(fā)光器件(OLEDs)三十年的發(fā)展歷程中,大量的發(fā)光材料被設計、開發(fā)、報道出來。盡管這些分子的結構各式各樣,但總結歸納起來基本都可以劃歸為四類體系:1.利用單線態(tài)激子發(fā)光的傳統(tǒng)熒光材料體系;2.利用三線態(tài)激子發(fā)光的磷光材料體系;3.利用三線態(tài)激子轉化為單線態(tài)激子的新型熒光材料體系,這其中包括:TTA、TADF以及HLCT材料體系;4.利用三線態(tài)激子與極化子作用轉化成單線態(tài)激子的TPI材料體系。而不同于上述所有的發(fā)光材料體系,2015年,我們組開創(chuàng)性地提出一種利用雙線態(tài)激子發(fā)光的機制,并首次利用一個開殼自由基分子TTM-1Cz(咔唑與TTM的加合物)做發(fā)光層,實現(xiàn)了較高效率的近紅外電致發(fā)光。對于開殼自由基分子,其前線軌道(SOMO)上只有一個單電子,所以當分子受到激發(fā)后,單電子躍遷到更高的能級軌道,其原來所占據(jù)的軌道就會變?yōu)榭哲壍?這時,電子往基態(tài)的躍遷就會變?yōu)橥耆试S的。因此,從理論上講,基于開殼分子的有機發(fā)光器件,其內(nèi)量子效率可以達到100%。但是,可以在空氣中穩(wěn)定存在的自由基種類比較受限,而能夠室溫發(fā)光的自由基分子就更為稀少;另一方面,由于自由基本身的性質,該類發(fā)光材料體系的發(fā)射基本都在深紅/近紅外區(qū)。因此,設計開發(fā)更多穩(wěn)定的發(fā)光自由基,豐富該類材料體系以及調(diào)控分子的發(fā)射波長使其覆蓋更寬的波長范圍,是一項很有意義而又富有挑戰(zhàn)性的工作,而且對于此類材料體系的研究仍有大量基礎工作需要開展。本論文依據(jù)雙線態(tài)激子的發(fā)光機制,基于穩(wěn)定中性的三-(2,4,6-三氯苯)甲基自由基(TTM)衍生物具體開展了以下兩部分內(nèi)容的工作:1.基于TTM和給電子含氮雜環(huán)吲哚單元的修飾合成及光電性能研究。我們選取給電子含氮雜環(huán)吲哚分子作為修飾單元,同時注意到吲哚雖然比咔唑的給電子能力略強,但是分子結構上少一個苯環(huán)會導致共軛程度明顯降低。我們將吲哚連接到TTM苯環(huán)的對位碳上,合成出具有不同取代基數(shù)目的TTM-1ID和TTM-2ID。兩個分子具有明顯的分子內(nèi)電荷轉移(ICT)性質,它們的發(fā)射光譜相比TTM紅移,相比TTM-1Cz藍移。兩個材料的電致發(fā)光(EL)波長都在650 nm左右,并且獲得了在不同電壓下都比較穩(wěn)定的光色。CIE坐標分別為(0.649,0.306)和(0.667,0.301),接近美國國家電視標準委員會(NTSC)制定的紅光標準。器件的最大外量子效率分別為1.8%和2.4%,尤其是基于TTM-2ID的電子器件,其雙線態(tài)激子生成比例達到了接近100%的水平。然而,兩個分子較低的薄膜熒光效率限制了器件性能的進一步提高。2.基于TTM和拉電子含氮雜環(huán)苯并咪唑的修飾合成及光電性能研究。出色的器件性能需要能同時具備高發(fā)光效率和高激子生成比例的發(fā)光材料。所以在第二部分工作中,我們選取常見的吸電子基團苯并咪唑作為修飾單元,制備合成了兩個新穎的具有不同取代基數(shù)目的開殼自由基分子TTM-2Bi和TTM-3Bi。我們通過抑制分子的ICT程度,既調(diào)控了發(fā)光波長的進一步藍移,同時又大大提高了其摻雜薄膜的光致發(fā)光效率�；趦蓚�材料的摻雜器件都展現(xiàn)出了出色的穩(wěn)定性和抗電壓擊穿特性。兩個器件的最大外量子效率分別達到了5.4%和4.1%,尤其是基于TTM-2Bi的電致發(fā)光器件,其最大外量子效率更是超過了傳統(tǒng)熒光OLED外量子效率5%的理論上限,兩個器件的激子生成比例也分別達到了69%和57%。
[Abstract]:In organic electroluminescent devices (OLEDs) thirty years of development, a large number of luminescent materials was designed, developed, reported. Although the structure of every kind of these molecules, but summarized up basically can be divided into four categories: 1. system singlet exciton emission of the traditional fluorescent material by three line system; 2. exciton emitting phosphorescent material system; 3. by three excitons into new fluorescent material system of singlet excitons, which include: TTA, TADF and HLCT material system; 4. using three excitons and polaron effect into singlet exciton TPI material system. Different from all of the above luminescent materials the system, in 2015, our group put forward a double use state exciton luminescence mechanism, and use an open shell free radical TTM-1Cz first (carbazole TTM adducts) as the emitting layer to achieve a more Near infrared light emitting efficiency. For open shell molecules, the frontier molecular orbital (SOMO) only a single electron, so when the molecule is excited by single electron transition, to a higher level of its original track, occupy the track will become empty track, then the electronic transitions will go the ground becomes fully allowed. Therefore, theoretically, organic light emitting devices based on open shell molecules, the internal quantum efficiency can reach 100%. but can free radicals are stable in the air is limited to free radicals at room temperature luminescence is even more scarce; on the other hand, because of the basic properties of the free body, the light emitting material system of emission basically in the red / near-infrared region. Therefore, the design and development of more stable emission free radicals, rich the material system and molecular emission wavelength to cover a wider wave Long range is a meaningful and challenging work, and Research on this material system still has a lot of work needs to be done. This paper is based on the double exciton luminescence mechanism, based on stable neutral three - (2,4,6- three -) methyl radical (TTM) derivatives as follows two part of the contents of the work: 1. based on TTM and electron heterocyclic indole unit modified synthesis and photoelectric properties research. We selected for electronic heterocyclic indole molecules as the modified unit, noting that although the electron than indole carbazole ability stronger, but less on the molecular structure of a benzene ring will lead to obvious degree of conjugation we will be reduced. Connect to the TTM indole para carbon benzene, synthesized with different substituents to TTM-1ID and TTM-2ID. two molecules with obvious intramolecular charge transfer (ICT) properties of it The emission spectra of TTM compared with redshift, compared to the TTM-1Cz blue shift. Two el (EL) wavelength around 650 nm, and obtained the.CIE color coordinates in different voltages are relatively stable respectively (0.649,0.306) and (0.667,0.301), close to the United States National Television Standards Committee (NTSC) red standard. The maximum external quantum efficiency of the device were 1.8% and 2.4%, especially in electronic devices based on TTM-2ID, the double exciton generation has reached a level close to 100%. However, the film fluorescence efficiency of two molecules of lower limit device to further improve the performance of.2. modified synthesis and photoelectric properties of TTM and electron withdrawing nitrogen containing heterocyclic benzimidazole based on devices with excellent performance. It can also have the luminescent materials of high luminous efficiency and high exciton generated proportion. So in the second part, we choose common The electron withdrawing groups as modified benzimidazole unit, has synthesized two novel with different substituents to open shell radicals TTM-2Bi and TTM-3Bi. inhibited us by ICT molecules, which regulate further blue emitting wavelength shift, but also greatly improves the efficiency of the light emitting light. Based on doped doped thin films device two materials showed excellent stability and anti voltage breakdown characteristics. The maximum external quantum efficiency of two devices respectively reach 5.4% and 4.1%, especially TTM-2Bi electroluminescent devices based on the maximum external quantum efficiency is more than the theoretical upper limit of traditional fluorescent OLED external quantum efficiency of 5%, exciton the proportion of the two generation devices are respectively 69% and 57%.

【學位授予單位】：吉林大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O626

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5 Jubert;A.H;Castro;E.A.;;BEBO改良法計算甲基自由基攫氫反應的活化能[J];化學學報;1986年10期

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