【作者】 段桂花；

【导师】 马於光； 张厚玉；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2010， 博士

【摘要】 有机光电材料的载流子传输性质是影响有机半导体器件性能的重要因素。研究其结构对载流子的传输性质的影响对开发和应用新型有机光电材料至关重要。本论文以几类有机光电材料固态晶体结构的载流子迁移率为主要研究内容,深入探讨了材料的结构(如取代基,共轭π分子体系的大小,分子的堆积模式等)对其传输性质的影响。预测的固态载流子的迁移率与实验值具有可比性,为设计和合成新的具有高载流子迁移性质的有机光电材料提供了理论依据。论文从研究有机光电材料分子的几何结构和电子结构入手,计算了分子的重组能,分析了其在品体结构中主要的传输路径和电荷转移积分,由此预测材料的迁移率。主要包括以下四部分内容：1以三联苯为骨架十字交叉型π共轭体系,其空穴重组均小于电子的,更利于空穴传输；空穴的传输主要是通过三联苯方向上两端苯环的“边对面”的相互作用及分子中心π体系的错位重叠相互作用来实现。取代基不同,其电荷分布有很大区别,引入适当的取代基,更利于电荷的二维离域；引入氰基后,空间位阻增大,传输路径明显减少,但分子间的有效重叠较大,迁移率明显提高,空穴迁移率提高10倍以上,电子迁移率提高近3倍；DDBB与DPDSB传输路径相同,但其空穴迁移率比DPDSB高30倍,电子迁移率高100倍。2蒽类衍生物具有较高的载流子迁移率,理论计算与实验结果相符。由于侧链取代基有较强的分子间范德华力,分子间堆积比较紧密,有利于载流子传输。引入适当的取代基,可以提高载流子的迁移率,同时可以实现材料由空穴传输向电子传输的转变。3含有"chalcogenophene"的杂环芳化合物,在侧链引入对称取代基后,重组能增大,空穴传输积分减小,电子传输积分略有增大；以BTBT为基体的化合物具有更好的电荷传输能力；引入共轭性好的取代基(DNTT),可增大分子的共轭,形成更大的离域π键,形成更密集的分子堆积,更利于分子间电荷的有效传输；引入苯基后,其空间位阻大大增大,虽然通过引入苯基可以提高其共轭能力,但其空间位阻效应对载流子传输的影响更大,因此,引入取代基要同时考虑引入取代基后的共轭效应和空间位阻效应的影响。4不对称杂环并苯Ar-BFC,其HOMO轨道较均匀的分布在整个共轭体系中,而LUMO轨道主要在共面的杂并苯环上；化合物Ph-BFC是很好的双极性材料,引入烷氧基后,其重组能增大,但空穴传输能力增强,而电子的传输能力减弱；对传输能力其决定性作用的是其传输路径。分子间的共面不平行的堆积对电荷传输起决定性作用。更多还原

【Abstract】 Charge Carrier transfer property of organic optoelectronic material is an important factor affecting the performance of an organic semiconductor, and therefore it is crucial to study the effect of the structure of organic optoelectronic materials on carrier transport property for development and application of new organic photovoltaic materials. This thesis focuses on the mobility of the carriers of several types of organic optoelectronic materials with solid-state crystal structure and deals with the effects of structures(such as substituent, the size of theπconjugated molecular system and molecular stacking) on the transport properties. It can provide a theoretical basis for experimental design. We studied the impact of substituent groups on molecular and electron structure, calculated the reorganization energy, analyzed molecular transfer path and calculated the transfer integral of each path, and predicted the mobility of the solid state carriers. This thesis mainly covers the following parts:1 We researched electronic structure and crystal carrier transport properties of the cross typeπ-conjugated molecules DPDSB, CNDPDSB and DDBB. We mainly explored impact of three different kinds type terphenyl of substituents on the cross molecule for skeleton. The results show that, the hole reorganization energy are all less than that of an electron, which is beneficial to the hole transport.. Charge distribution of a molecule with different substituents is very different. The introduction of appropriate substituents can reach the two-dimensional molecular structure of conjugation, which is conductive to the space charge delocalization. Different substituents of molecules have quite different transfer paths. Because the effective overlap between the molecules is larger, the mobility of hole has increased by 10 times and 3 times for electron. For molecule DDBB, having a more delocalized charge distribution, its hole mobility is 30 times higher than that of DPDSB,100 times higher than that of electron.2 We researched molecular and electronic structure, reorganization energy and charge-transfer integral of symmetric substituted anthracene derivates, and using Einstein relation calculated the carrier mobility at room temperature. The results show that anthracene derivates has a high carrier mobility as the same as pentacene. Calculation value is consistent with the experiment results. Due to strong intermolecular interaction, the intermolecular stacking is denser, it is conductive to the carrier transport. But also it can be found by calculating that the introduction of appropriate substituents, the change from hole transfer to electronic transfer can be achieved. This is to provide for a theoretical basis for their applications. The introduction of the appropriate substutuents, in enhancing the stability of the materials, at the same time, is more conductive to the transfer of carrier. These studies can provide a theoretical basis for the practical application of three anthracene derivates.3 Heterocyclic aryl compounds containing "chalcogenophene" BSBS, DNTT, Ph-BSBS, C12BTBT and C12BSBS are researched, we studied the molecular and electronic structure, calculated the reorganization energy, transfer integral and carrier mobility of the crystal structure. The results show that after introduction of symmetrical substituents in the side chain of BSBS, the molecules steric hinderance increases, the reorganization of the molecules increases, the intermolecular hole transfer integral decreases, and the electrons transfer slightly increases, the introduction of substituents greatly enhances the solvency of compounds. BTBT as the base compound has a better charge transfer capacity than BSBS. furthermore, BTBT can reduce costs in the application, at the same time, can avoid toxicity and pollution caused by selenium. This provides theoretical basis for design of new materials. Introducing well conjugated groups in the matrix can greatly increase the performance of molecular conjugation, so molecules form a larger delocalizedπbond, and form a more dense molecular stacking, while reduce the molecular reorganization energy. So is more conducive to the effective intermolecular charge transfer. For DPh-BSBS, after the introducing of phenyl, its steric greatly increases. Although the introducing of phenyl can enhance the ability of conjugation, the steric hinderance has more effect on the transport of charge carrier. We calculated that the mobility at room temperature is less than without substituents or with alkyl, but is slightly enlarged for electronic mobility. It was found that the introducing of appropriate substituents, in enhancing the stability of the materials, at the same time, is more conductive to the transfer of carrier. The introduction of the substituent needs to consider both the conjugation and the steric hindrance effect.4 We researched the molecular and electronic structure, molecular reorganization energy, charge transfer integral of the asymmetric heterocyclic acene containing pyrrole and furan rings Ar-BFC(1.R=H,2.R=OC6H13,3.R=OC10H21), using Einstein relation we calculated the carrier mobility at room temperature. The results show that Ph-BFC is a preferable bipolar material。The mobility of hole at room temperature is 0.88 cm2/V·s, and is 0.53 cm2/V·s for that of electron. After introducing the alkoxy, the ability of hole transfer enchances for molecules 4-OC6H13-Ph-BFC and OC10H21-Ph-BFC, while it weakens for electronic transfer, for 4-OC10H21-Ph-BFCthe mobility of hole is 1.75 cm2/V·s, and is 0.10 cm2/V·s for that of electron at room temperature. So it is more conducive for hole transfer. Interaction of intermolecular non-parallel coplanar for heterocyclic acene and edge to face interaction of side benzene ring and common-plane heterocyclic acene are major factor effecting the hole transfer. Interaction of intermolecular non-parallel coplanar for heterocyclic acene is key factor for electronic transfer. So the interaction of intermolecular non-parallel coplanar for heterocyclic acene is the crucial factor for the transfer of carrier. This provides a new way of design high mobility carrier-transporting materials. This is also provides a theoretical basis for the molecules in organic field-effect transistors as the active layer of the potential application.更多还原