氮杂红荧烯类有机半导体材料的设计与合成

Recently, organic semiconductors with fused rings are the focus of considerable interest in the emerging area of organic electronics and photonic decvices. Over the past years, many groups have aimed to synthesize electron transport organic semiconductors with high electron affinities, comprising specific electron with- drawing groups, such as -F, -Cl, -C=O, -CN. .Here, we explore a new strategy for designing high performance ambipolar or n-type organic semiconductors based on aza-rubrene derivatives. A series of aza-rubrene based organic semiconduvtors will be synthesized by introducing electronegtive N atoms into the backbone of rubrene. Optical properties of these new materials will be characterized by UV-vis spectra and fluorescence spectra. Thermal stabilities of these compounds will be investigated by differential thermal analysis (DSC) and thermogravimetric analysis (TGA). The energy levels of these molecules will be caculated by density functional theory (DFT) and cyclic voltammetry (CVs). Single crystal arrangements in solid states of these new materials will be characterized, which provide the opportunity to understand the relationships between molecular structure and various physical properties. Organic field-effect transistors (OFETs) based on these aza-rubrene compounds will be fabricated, and their charge carrier mobilites were investigated. We expect to be able to prepared several high mobilities ambipolar or n-type semiconductors based on aza-rubrene molecules. The finding of this work provides a general guideline for designing high performance ambipolar organic or n-type semiconductors based on aza-rubrene in future.

有机半导体材料在未来有机电子领域有着重要的应用价值，开展对新型有机半导体材料的设计、合成具有重要意义。双极性或n-型有机半导体材料是目前研究相对较少的半导体材料，传统上是通过在p-型分子骨架外引入吸电子取代基来合成的。.本课题突破传统的方法，在p-型分子红荧烯骨架内引入吸电子的N原子，通过降低分子的最低空轨道(LUMO)能级，设计合成具有电子传输性能的氮杂红荧烯类有机半导体材料。用紫外光谱(UV-vis)、荧光光谱(FL)、循环伏安法(CVs)、差热分析(DSC)、热重分析(TGA)等手段对所合成新分子的基本性质进行表征；利用密度泛函理论(DFT)对该系列氮杂红荧烯分子的轨道能级进行理论计算；解析该系列分子的单晶结构，分析固态下分子的堆积方式；以该系列新分子为有源层制备有机场效应晶体管(OFETs)，测试其载流子迁移性质，获得高性能的双极性或n-型有机半导体材料。

有机半导体材料因可以制备廉价的、便携的电子器件或光电器件而引起了人们广泛的关注，比如：有机发光二极管 (OLEDs)、有机场效应晶体管（OFETs)、柔性显示屏、CMOS反相器、有机太阳能电池 (OSCs)等。 . 在本项目中，通过将N原子引入到p-型有机半导体材料并五苯、并四苯和其它大π共轭体系分子中，合成了多种新型有机半导体材料，比如氮杂并五苯、氮杂红荧烯、氮杂还原黄G等。通过对分子的OFET性质的表征测试，发现将N原子或卤素原子引入到p-型半导体分子骨架中，使其转变为双极性或n-型有机半导体材料，其中两个分子的空穴和电子迁移率均达到0.2 cm2 V−1 s−1以上。同时，利用氮杂并五苯分子为有源层制备的CMOS反相器，具有非常优异的性能，电压增益达到160以上。