本文選題：有機電致發(fā)光 + 熱活性型延遲熒光�。� 參考：《哈爾濱工業(yè)大學》2016年碩士論文

【摘要】：有機熱活性型延遲熒光(Thermally Activated Delayed Fluorescence,TADF)材料可以在無貴金屬的條件下實現(xiàn)100%的內(nèi)量子效率,成為當前有機電致發(fā)光領域最活躍的研究熱點之一。與熒光材料和磷光材料相比,有機TADF材料具有成本低、發(fā)光效率高等優(yōu)點,被稱為第三代電致發(fā)光材料。本論文設計了一系列具有TADF性質的有機分子,并基于密度泛函理論系統(tǒng)研究了其基態(tài)和激發(fā)態(tài)的幾何構型,前線分子軌道,吸收、發(fā)射光譜,振子強度以及最低單重激發(fā)態(tài)-三重激發(fā)態(tài)能隙(ΔEST)等性質,從本質上揭示了分子結構與光物理性質之間的關系。主要研究內(nèi)容如下:(一)以9-氫-噻噸-9-酮-10,10-二氧化物為受體(Acceptor,A),分別引入二苯胺、咔唑、9,9-二甲基-9,10-二氫吖啶、吩VA嗪四種不同的給體(Donor,D),以苯環(huán)(Ph)為連接橋,設計了D-A型、D-Ph-A型、D-A-D型、D-Ph-A-Ph-D型共16種噻噸酮類衍生物分子�；谧顑�(yōu)Hartree-Fock交換方法預測了其TADF性質,深入研究了不同給體、Ph橋、雙給體對TADF性質的影響。結果表明:對于D-A型分子,給體的空間位阻是影響ΔEST的決定性因素,空間位阻越大,ΔEST越小;引入Ph橋雖能夠減小HOMO和LUMO重疊,但并不一定能夠減小ΔEST,而引入雙給體則對ΔEST幾乎沒影響。計算發(fā)現(xiàn)有7種分子ΔEST較小,同時具備一定的最優(yōu)垂直吸收和發(fā)射振子強度(fVA(OHF)和fVE(OHF)),可能具有高效的TADF性質。本工作設計的一種分子(1d分子)的發(fā)射波長和ΔEST幾乎與實驗中的一種高效黃光TADF分子(1b分子)完全一致,但1d分子的fVA(OHF)和fVE(OHF)明顯強于1b分子(分別增加了0.0323和0.0168),表明1d分子可能是一種更為高效的黃光TADF分子。(二)以N3,N3,N6,N6-四苯基-9-(4-(喹喔啉-6-基)苯基)-9H-咔唑-3,6-二胺分子(DACQ)為母體,通過引入不同給、吸電子取代基以及改變給、受體連接位置設計了8種喹喔啉類衍生物分子�；谕瑯拥姆椒A測了其TADF性質,深入研究了取代基以及給、受體連接位置對TADF性質的影響。結果表明:在DACQ的受體上引入給電子取代基(-OCH3、-CH3)以及改變給、受體的連接位置,并不能降低ΔEST,但引入吸電子取代基(-2F、-4F與-CN),則可明顯減小ΔEST,且分子的吸收和發(fā)射波長明顯紅移。其中分子7的發(fā)射波長為590 nm,fVA(OHF)和fVE(OHF)分別為0.1737和0.0954,ΔEST為0.093 eV。較小的ΔEST和較大的振子強度表明該分子可能是一種高效的黃光TADF分子。分子8和9的發(fā)射波長分別為660和680 nm,ΔEST分別為0.096和0.092 eV,兩者都為紅光TADF分子。與分子8相比,分子9具有更高的fVA(OHF)和fVE(OHF)(分別為0.2231和0.1061),表明分子9可能是一種更為高效的紅光TADF分子。
[Abstract]:Thermally Activated Delayed delay fluorescence (TADF) materials with organic thermal activity can achieve an internal quantum efficiency of 100% without precious metals, which has become one of the most active research topics in the field of electroluminescence. Compared with fluorescent and phosphorescent materials, organic TADF materials have the advantages of low cost and high luminescence efficiency, so they are called the third generation electroluminescent materials. In this paper, a series of organic molecules with TADF properties are designed, and the geometric configurations of ground and excited states, frontier molecular orbitals, absorption and emission spectra are systematically studied based on density functional theory. The properties of oscillator strength and the lowest singlet excited triple-excited state gap (螖 EST) reveal the relationship between molecular structure and photophysical properties in essence. The main contents of this study are as follows: (1) four different donors, Donor Dy, were introduced as follows: (1) four different donor DonorDwith benzene ring Phi, respectively, diphenylamine, carbazolium 9-dimethyl-9-dimethyl-10-dihydroacridine, phenylethoxazine and phenylephrine, with 9H-thio-ton-9-keto-10- (10-) -dioxide as the acceptor. A total of 16 kinds of thiadione derivatives were designed for D-A and D-Ph-A, D-A-D and D-Ph-A-Ph-D, respectively. Based on the optimal Hartree-Fock exchange method, the TADF properties are predicted, and the effects of different donor Ph bridges and double donors on the TADF properties are studied. The results show that for D-A molecule, the steric resistance of donor is the decisive factor affecting 螖 EST, the larger the steric resistance is, the smaller the 螖 EST is, while the introduction of Ph bridge can reduce the overlap between HOMO and LUMO. However, 螖 ests are not necessarily reduced, and the introduction of double donors has little effect on 螖 EST. It is found that there are 7 molecules with small 螖 EST, and some optimal vertical absorption and emission oscillator intensities (fVAHV) and fVEOHF (OHF), which may have high TADF properties. The emission wavelengths and 螖 EST of a molecular molecule (1 d) designed in this work are almost identical to that of a highly efficient yellow light TADF molecule (1 b). However, the fVAHV) and fVEOHF of 1d molecule were significantly stronger than that of 1b molecule (0.0323 and 0.0168), respectively, indicating that 1d molecule might be a more efficient yellow light TADF molecule. (2) with N _ 3N _ 3N _ 3N _ 6N _ 6N _ 6- tetraphenyl -9-Or (quinoxaline -6-yl) phenyl--9H-carbazole-6-diamine molecule as the parent, eight derivatives of quinoxaline derivatives were designed by introducing different electron substituents and changing the acceptor sites. Based on the same method, the properties of TADF are predicted, and the effects of substituents and sites of acceptor junctions on the properties of TADF are studied. The results show that the insertion of electron substituent (OCH _ 3H _ 3H _ 3) and the change of the acceptor position can not decrease 螖 estr, but the absorption and emission wavelengths of the molecule are obviously red-shifted when the electron absorbing group is introduced into the acceptor of DACQ, and the absorption and emission wavelengths of the molecule are obviously red-shifted, if the electron absorbent group is introduced into the acceptor and the electron absorbing group is substituted by the electron acceptor -2F _ (-4F) and -CNN _ (+). The emission wavelengths of molecule 7 are 0.1737 and 0.0954, respectively, and the 螖 EST is 0.093 EV. The smaller 螖 EST and larger oscillator strength indicate that the molecule may be a highly efficient yellow light TADF molecule. The emission wavelengths of molecule 8 and 9 are 660 and 680nm, respectively, and 螖 EST are 0.096 and 0.092 EV, respectively. Both of them are red light TADF molecules. Compared with molecule 8, molecule 9 has higher fVAHv) and fVEOHFH (0.2231 and 0.1061g, respectively), indicating that molecule 9 may be a more efficient red light TADF molecule.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TN383.1
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本文編號：1883871