【作者】 薛金强；

【导师】 冯亚青；

【作者基本信息】 天津大学 ， 应用化学， 2008， 博士

【摘要】 新型红色有机电致发光材料的研究和开发对有机发光器件的全彩色平板显示具有重要意义。卟啉化合物由于其独特的发光性能是一种理想的红色掺杂染料,目前虽然卟啉掺杂的红色发光器件在发光色纯度方面具有很好的应用前景,但还存在其制备的器件发光效率和发光亮度都较低等问题。本文通过增大卟啉分子的共轭结构或将具有高荧光量子产率的基团（苯并唑或香豆素）连接到卟吩环的中位得到了四类共20个新型的卟啉化合物,并选取其中10个化合物制备有机发光器件来考察材料的电致发光性能,具体内容包括以下几个部分:设计合成了3个中位直接被三芳胺取代的卟啉化合物4a-c和3个通过苯乙烯连接的卟吩-三芳胺共轭体10a-c,通过核磁氢谱、质谱、紫外吸收光谱和荧光发射光谱表征了新化合物的结构。经紫外吸收光谱和荧光发射光谱研究表明在化合物4a-c和10a-c分子中三芳胺基团与卟吩母体之间有很好的能量传递,使得三芳胺基团吸收的能量通过卟啉发色团发射出去。采用具有强烈荧光的反式二苯乙烯及其衍生物修饰卟吩的中位,合成了6个卟啉化合物26a-f,并通过核磁氢谱、质谱、紫外吸收光谱和荧光发射光谱表征了它们的结构。由于共轭程度的增加,化合物的紫外吸收光谱和荧光发射波长较四苯基卟啉（TPP）有10 nm左右的红移。将苯并唑类基团（苯并咪唑、苯并噁唑和苯并噻唑）引入到卟吩中位,得到5个新型卟啉36a-e衍生物,并经核磁氢谱、质谱、紫外吸收光谱和荧光发射光谱表征了化合物的结构。由于N、O和S杂原子的引入降低了卟啉衍生物的摩尔消光系数,因而紫外吸收较弱,但化合物36a-e荧光发射能力增强。将强荧光母体香豆素引入到卟吩的中位得到3个荧光染料44、45和46,并通过核磁氢谱、质谱、紫外吸收光谱和荧光发射光谱表征了新化合物的结构。由于香豆素取代卟啉分子中较大的空间位阻和环内C=O的存在,导致化合物44、45和46的最大荧光发射峰出现在710 nm附近,而在650 nm左右有一个弱的肩带,这与一般卟啉化合物的荧光发射光谱刚好相反。以卟啉26f为例详细研究了分别掺杂在电子传输材料8-羟基喹啉铝（Alq₃）和空穴传输材料N,N′-二苯基-N,N′-二（3-甲基苯基）-1,1′-联苯-4,4′-二胺（TPD）中以及不同掺杂浓度下的电致发光性能。Alq3用作主体材料制备的器件在发光亮度和发光效率方面比掺杂在TPD中制备的器件性能好,但TPD用作主体材料制备的器件具有很高的色纯度。当26f在TPD中以摩尔分数1.5%掺杂时制备的器件发射出红光,最大亮度和外量子效率分别为73 cd/m2和0.0365。在相同条件下制备了其余9个化合物在TPD中的掺杂器件,并比较了在相同器件制备条件下不同系列卟啉化合物的电致发光性能。其中由化合物46掺杂制备的器件有最好的发光性能,其最大发光亮度和外量子效率分别为102 cd/m2和0.0408,此时发射光的色坐标为x=0.5703,y=0.3217。更多还原

【Abstract】 It is vitally important to research the red emitting materials for developing full-color display of OLEDs. Porphyrins compounds are ideal red doping materials due to their unique luminescence properties, presently, the saturated red emission of red OLEDs doped by porphyrins is satisfactory for practical use, but there exist some problems, such as quantum efficiency and luminance of OLEDs are both low.In this paper, twenty novel meso-substituted porphyrins of four series were designed and synthesized by increasing the conjugation of porphyrins or introducing substituents (such as benzoazole, coumarin) with high fluorescence quantum yield into the meso-position of porphine, and then red OLEDs were fabricated by doping porphyrins into a suitable host using ten porphyrins compounds and their electrolumin -escence properties were tested. The main contents and results were generalized as follows:Three meso-tetrakis(triarylamine substituents)porphyrins 4a-c and three conjugations of porphine-triarylamine linked by styrene 10a-c were synthesized and characterized by 1H NMR, MS, UV-vis spectra and fluorescence emission spectra. The electronic interaction between the triarylamine units and porphines macrocycle in 4a-c and 10a-c were investigated by UV-vis absorption spectroscopy and fluorescence emission spectroscopy, and the results showed that there was a good energy transfer between triarylamine units and porphines. Thus, the absorbed energy by triarylamine units was reemitted by the porphyrins chromophore.Six porphyrins compounds 26a-f were obtained by introducing intensely fluorescence chromophore trans-stilbene, and characterized by 1H NMR, MS, UV-vis spectra and fluorescence emission spectra. Their UV-vis absorption spectra and fluorescence emission spectra were red shifted about 10 nm compared to tetraphenylporphyrin(TPP) as a consequence of expandedπ-conjugation.We firstly introduced benzoazole (including benzimidazole, benzoxazole and benzothiazole) into the meso-positions of porphines and obtained five new porphyrins 36a-e. Their structures were characterized by 1H NMR, MS, UV-vis spectra and fluorescence emission spectra. The molar extinction coefficient was lowered because of the presence of heteroatom (nitrogen, oxygen or sulphur) in above-mentioned molecules, so the UV-vis absorption was weakened, but the brightness of 36a-e fluorescence was increased.Due to their significant fluorescence chromophores, coumarins were introduced into the meso-positions of porphines and compounds 44, 45 and 46 were synthesized. Then their structures were characterized by 1H NMR, MS, UV-vis spectra and fluorescence emission spectra. The fluorescence spectra of 44, 45, 46 had a maximal peak at about 710 nm and a weak shoulder at about 650 nm because of steric hindrance and presence of C=O, and this was on the contrary of others porphyrins fluorescence spectra.To study the electroluminescence performance of 26f, the OLEDs devices were prepared with 26f as dopant and tris(8-hydroxyl quinoline)aluminum (Alq3) or N,N′-diphenyl-N,N′-di(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD) as host, and we studied the electroluminescence properties at different doping concentration. The luminance and efficiency of OLEDs were better than TPD when Alq3 was used as host, but the luminescence color was more pure when TPD was used as host. When the doping concentration of 26f in TPD was 1.5%, the luminescence color of OLED was red, and the maximal luminance and external quantum efficiency were 73 cd/m2 and 0.0365, respectively. The other nine OLEDs devices were fabricated with porphyrins as dopants and TPD as host, and we evaluated the electroluminescence performances of different series porphyrins at the same fabrication conditions of OLEDs. The best electroluminescence properties were obtained when 46 was used as dopant, and the maximal luminance and external quantum efficiency were 102 cd/m2 and 0.0408, respectively. The CIE coordinates were x=0.5703, y=0.3217.更多还原