含氰基吡啶及三唑双偶极主体材料的合成及性能研究

发布时间：2018-01-19 00:26

本文关键词： 咔唑氰基吡啶三唑双偶极主体材料有机电致发光　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：由于具有驱动电压低,功耗小,对比度高,主动发光,质轻体薄,可柔性显示等诸多优点,有机电致发光二极管(OLEDs)逐渐发展成新一代平板显示技术中最有力的竞争者,广泛应用于电视、手机和可穿戴设备等诸多电子产品上。在OLEDs所有的功能层中,发光层是最核心的部分,因此这一层材料的结构设计至关重要。目前,几乎所有的有机电致发光器件(包括荧光器件和磷光器件),其发光层均采用主-客体掺杂型的器件结构。双偶极主体材料因为同时具备电子和空穴的传输能力,使发光层中的载流子传输更加平衡,能够大幅度提高器件的发光效率,因此是发光层主体材料的最佳选择。咔唑及其衍生物具有优秀的空穴传输能力,而且其自身三线态能级较高,作为优良的P型传输基团,广泛用于空穴传输材料上。三唑类化合物、含氰基的化合物和吡啶衍生物等是具有较好的电子传输能力,它们作为优良的N型传输基团,被用于电子传输材料。本论文选用咔唑为空穴传输基团,氰基吡啶及三唑为电子传输基团,设计并合成了七个双偶极主体材料m-CzPyCN、n-CzPyCN、o-CzPyCN、t-CzPyCN、DzSCz、DzDCz和SzDCz。为了保证目标分子具有较高的三线态能级,本文利用常规的分子设计方法,即利用间位取代和邻位取代具有较大的空间位阻效应,缩短分子的共轭长度,使得分子的donor与acceptor空间分离,设计合成了氰基吡啶系列和三唑系列共7个双偶极分子。利用带边吸收和循环伏安相结合的方法,计算并得到分子的HOMO与LUMO能级,利用Gauss03计算分子轨道的空间分布情况并以此为基础优化分子空间结构。计算结果显示,在这些分子中HOMO跟LUM O基本完全分离,三线态能级较高,适合做绿光和蓝光的主体材料。以氰基吡啶系列材料做Ir(ppy)3的主体,三唑系列材料做FIrpic的主体,制备了有机电致发光器件,研究了这些双偶极主体材料的电致发光性能。结果显示,以氰基毗啶系列为主体材料制备的掺杂型绿光材料器件中,o-CzPyCN表现出最优异的性能,最大电流效率高达60 cd/A,比相同器件结构的间位取代主体材料m-CzPyCN的电流效率高一倍；三唑系列掺杂蓝光材料器件中,SzDCz表现出最优异的性能,其效率分别为27.8 cd/A,21.9 lm/W和12.9%,结果表明在双偶极主体材料设计中要根据电子传输基团和空穴传输基团的传输性能,合理调节它们的比例才能得到最佳性能的主体材料。
[Abstract]:It has many advantages, such as low driving voltage, low power consumption, high contrast, active luminescence, thin body weight, flexible display and so on. Organic light-emitting diodes (OLEDs) have gradually developed into the most powerful competitors in the new generation of flat panel display technology, widely used in television. The luminous layer is the core of all the OLEDs functional layers, so the structural design of this layer is crucial. Almost all organic electroluminescent devices (including fluorescent devices and phosphorescence devices). The photoluminescence layer is both host-guest doped device structure. Because of the transmission ability of electron and hole, the carrier transport in the luminescent layer is more balanced. Carbazole and its derivatives have excellent hole transport ability and their three-wire energy levels are higher. As an excellent P-type transport group, it is widely used in hole transport materials. Triazole compounds, cyano-containing compounds and pyridine derivatives have good electron transport ability. In this paper, carbazole was selected as the hole transport group, and cyanopyridine and triazole were selected as electron transport groups. Seven dipolar host materials m-CzPyCNN n-CzPyCNN + -PyCNT-PyCNT-PyCNT-DzSCz were designed and synthesized. DzDCz and SzDCz. in order to ensure that the target molecule has a higher three-line energy level, this paper uses the conventional molecular design method, that is, the use of interposition substitution and adjacent substitution has a larger steric resistance effect. The conjugate length of the molecule is shortened so that the donor of the molecule is separated from the acceptor space. Seven dipolar molecules of cyanopyridine series and triazole series were designed and synthesized. The HOMO and LUMO levels of the molecules were calculated and obtained by the method of band edge absorption and cyclic voltammetry. The spatial distribution of molecular orbitals is calculated by Gauss03 and the molecular spatial structure is optimized. The results show that HOMO and LUM O are completely separated in these molecules. The three-wire state is suitable for green and blue light materials, cyanopyridine series materials as the main body of Ir(ppy)3, triazole series materials as the main body of FIrpic. Organic electroluminescent devices (OLEDs) were prepared and their electroluminescent properties were studied. O-CzPyCN has the best performance, the maximum current efficiency is as high as 60 CD / A, which is twice as high as that of m-CzPyCN, which is the main substitute material of the same device structure. SzDCz exhibits the best performance in triazole doped blue-light devices, with efficiencies of 27.8 cd/ An 21.9 lm/W and 12.9% respectively. The results show that according to the transmission performance of the electron transport group and the hole transport group, the optimum performance of the host material can be obtained by adjusting their proportion in the design of the bipolar host material.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN383.1

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