几种氟代芳烃电荷传输性质的理论研究

发布时间：2018-10-26 22:05

【摘要】：有机半导体材料(OSCs)有着广泛潜在应用,其性能的优劣直接决定了有机器件性能的好坏。因此从微观理解并设计探究新型高性能有机半导体化合物具有重要的意义。本文采用密度泛函理论(DFT)并结合Marcus-Hush跃模型,对三类有机半导体材料体系进行了理论研究。1、选取了五种全氟代苯修饰寡聚噻吩单晶化合物,并计算了各个化合物电子和空穴重组能、电离能、电子亲和能以及电子和空穴迁移率等性质。结果显示增加噻吩环有利于降低LUMO轨道能级、降低重组能。这有利于电子的注入和空气稳定性的提升。其中A3的空穴迁移率(μh)D为0.72cm2·V-1·s-1,而A5的电子迁移率(μe)为0.19cm2·V-1·s-1,是潜在的有机半导体材料。2、对三吡咯苯(TPB,B1)进行局部吸电子基团取代设计了八种新型分子,并通过含色散力矫正的密度泛函方法(DFT-D)模拟计算了气态下该系列化合物平行二聚体的最稳定结构,并据此计算了改性化合物在二聚体间的电荷传输性能。结果表明氟化和氰基化导致电子亲和能明显增大,使得空气稳定性明显提升。预测B1,B2和B7的μe分别高达0.433 cm2·V-1·s-1,0.198 cm2·V-1·s-1和0.279 cm2·V-1·s-1,其中B7电子和空穴传输能力相当。B1,B2和B7是潜在的电子传输型有机半导体材料。3、通过对5,6,7-三硫并五苯-13-酮(TTPO,C1)分子进行氟取代,设计了三种TTPO衍生物C2、C3和C4。并通过Materials Studio软件中的CASTEP模块预测该系列化合物晶体结构,并据此研究其电荷传输性能。结果表明：氟化降低了这一系列化合物的LUMO/HOMO能级水平,提高了电子亲和能,增加其空气稳定性,并降低电子注入能垒。C1的电子和空穴迁移率分别高达1.01和0.62 cm2·V-1·s-1。经氟化的C2和C3的电子迁移率分别为0.38 cm2·V-1·s-1和0.33 cm2·V-1·s-1,满足实际应用要求。
[Abstract]:Organic semiconductor material (OSCs) has a wide range of potential applications, its performance directly determines the performance of organic devices. Therefore, it is of great significance to understand and design new high performance organic semiconductor compounds. In this paper, the density functional theory (DFT) and the Marcus-Hush model are used to study three kinds of organic semiconductor materials. 1. Five kinds of perfluorobenzene modified oligothiophene monocrystalline compounds are selected. The electron and hole recombination energy, ionization energy, electron affinity energy and electron and hole mobility were calculated. The results show that increasing thiophene ring can decrease the LUMO orbital energy level and reduce the recombination energy. This is beneficial to the injection of electrons and the improvement of air stability. The hole mobility of A3 (渭 h) D is 0.72cm2 V-1 s-1) and the electron mobility of A5 (渭 e) is 0.19cm2 V-1 s-1, which is a potential organic semiconductor material. 2, TPB,. B1) eight novel molecules were designed for the substitution of local electron-absorbing groups, and the most stable structures of parallel dimers in gaseous state were calculated by density functional method (DFT-D) with dispersion correction. The charge transport properties of the modified compounds between dimers were calculated. The results show that fluorination and cyaniding lead to the increase of electron affinity and the stability of air. The predicted 渭 e of B _ 1C _ 2 and B _ 7 are as high as 0.433 cm2 V-1 s-1G 0.198 cm2 V-1 s-1 and 0.279 cm2 V-1 s-1, respectively, in which the transport capacity of B7 electrons and holes is the same as that of B1. B2 and B7 are potential electron transport organic semiconductors. 3. Three TTPO derivatives C _ 2 C _ 3 and C _ 4 were designed by fluorine substitution of 5 ~ (6) C _ (6) -trithiobenzene-13-one (TTPO,C1) molecule. The crystal structure of the compound was predicted by CASTEP module in Materials Studio software, and its charge transport performance was studied accordingly. The results show that fluorination reduces the LUMO/HOMO level of these compounds, enhances the electron affinity and increases the air stability. The electron mobility of C1 is as high as 1.01 and 0.62 cm2 V-1 s-1, respectively. The electron mobility of fluorinated C2 and C3 are 0.38 cm2 V-1 s-1 and 0.33 cm2 V-1 s-1, respectively, which meet the requirements of practical application.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O649.5

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