【作者】 周敏；

【导师】 高希珂； 程探宇；

【作者基本信息】 上海师范大学 ， 有机化学， 2021， 硕士

【摘要】 萘二酰亚胺（NDI）是一类经典的电子受体单元,具有LUMO能级较低、化学稳定性高以及结构易修饰等特点,常用来构建n型有机半导体材料。无规共聚是一种向分子骨架引入第三组分的合成策略,常用来调控材料的电子能级吸收光谱以及结晶性等。该策略能够发展品种多样的有机半导体材料,满足实际应用的需求。材料的性能不仅与分子本身的性质有关,还受其聚集态结构的影响。手性能够诱导分子产生不同的聚集态结构。基于此,本论文设计合成了一系列萘二酰亚胺类无规共聚物和手性小分子,研究了其物理化学性质,并以它们为活性层材料制备了底栅极顶接触（BGTC）结构的有机场效应晶体管,研究了器件性能和结构性能关系。论文主要包括以下两个部分:1.选用两个结构异构的NDI受体单元（1,2,5,6-NDI和1,4,5,8-NDI）,与联二噻吩共聚合成了一系列无规共轭聚合物（P1-P5）,并用TGA、DSC、UV和循环伏安法研究了热学、光学和电化学等性质。TGA曲线显示该系列聚合物均具有较好的热稳定性,热分解温度均在450℃以上。紫外-可见吸收光谱表明控制不同受体单元的比例可调控聚合物的吸收光谱,且由P1到P5,聚合物的光学带隙逐渐变窄。同时,根据CV曲线可以计算出聚合物的LUMO能级,结果表明由P1到P5,LUMO能级呈现出下降的趋势（-3.64e V降至-3.82 e V）,这有效说明无规共聚能够对LUMO能级进行精细调控。此外,以该系列无规共轭聚合物为活性层材料制备了OFET器件。其中,P3表现出明显平衡的双极性特征(电子迁移率和空穴迁移率分别为1.29×10-3cm²V^-1s^-1和4.84×10-3 cm²V^-1s^-1),而P1表现为空穴主导,P5为电子主导,这说明无规共聚实现了载流子传输类型的调控。该研究结果为萘二酰亚胺类聚合物半导体材料的开发提供了参考和设计思路。2.手性可以诱导分子产生不同的聚集态结构从而影响材料的性能,因此我们将手性环己二胺引入1,4,5,8-NDI萘核的两端,合成了光学纯化合物（IV-5-R、IV-5-S）、内消旋化合物（IV-5-R,S）以及外消旋混合物（IV-5-rac）,并用TGA、DSC、UV、圆二色谱和循环伏安法表征了材料的理化性质。紫外-可见吸收光谱显示四者在二氯甲烷溶液中的吸收完全一致,即单分子状态下的光学性质相同,但薄膜状态下的吸收存在差异。消旋体材料的薄膜最大吸收峰较光学纯材料红移了约5 nm,这说明手性诱导产生了不同的聚集态结构。同时,还研究了它们的OFET器件性能,结果表明消旋体材料的聚集态结构更有利于载流子传输,其中内、外消旋体材料的空穴迁移率分别为0.074cm²V^-1s^-1和0.075 cm²V^-1s^-1,均高于光学纯材料IV-5-R和IV-5-S(空穴迁移率约为0.04 cm²V^-1s^-1)。该研究结果为萘二酰亚胺类有机功能分子的发展提供了新方向。更多还原

【Abstract】 Naphthalimide is a type of classic electron acceptor unit,which possesses low LUMO energy level,good thermostability and chemical modification.Therefore,it’s used to construct n-type organic semiconducting materials.As a synthetic strategy,random copolymerization is devoted to adjusting the electronic energy level,absorption spectrum and crystallinity,which could develop a variety of organic semiconducting materials to meet the needs of applications.The performance of the materials is not only related to the characteristic of molecule,but affected by the aggregation structure,respectively.In addition,the chirality can induce different aggregated state.In this paper,a series of organic optoelectronic functional materials based on naphthalimide were synthesized,then the corresponding physical and chemical properties were studied.What’s more,we also prepared the organic field-effect transistors with bottom-gate topcontact structure and tested their performance.The main contents of this thesis are as follow:1.A series of random conjugated polymers（P1-P5）were synthesized by 1,2,5,6-NDI,1,4,5,8-NDI and dithiophene.Meanwhile,the physicochemical properties were characterized by TGA,DSC,UV-vis and cyclic voltammetry.All polymers had good thermal stability（Td > 450 ℃）,and the ultraviolet absorption spectrum showed the different ratio of two acceptor units could adjust the absorption range of the materials,respectively.Furthermore,the CV curves indicated that random copolymerization did achieve to adjust the LUMO energy level.In addition,the OFET device based on P3 showed quite balanced bipolarity(μe=1.29 × 10-3 cm²V^-1s^-1,μh= 4.84 × 10-3 cm²V^-1s^-1),while P1 and P5 both displayed uncoordinate bipolarity(P1 was dominated by hole carrier with 0.132 cm²V^-1s^-1,P5 was dominated by electron carrier with 0.03 cm²V^-1s^-1).It proved the random copolymerization realized the regulation of the type of carrier transport.The result will provide valuable insights for the development of naphthalimide polymer.2.Chirality could induce different aggregated structures then affect the properties of materials.Therefore,we designed and synthesized the optically pure compounds（IV-5-R,IV-5-S）and mesomer（IV-5-R,S）,moreover obtained racemic mixture（IV-5-rac）by mixing IV-5-R and IV-5-S equimolarly.The physical and chemical properties were characterized by TGA,DSC,UV,circular dichroism and cyclic voltammetry.The UV absorptions in solution were consistent,while the absorptions in film were slightly different,indicating the unequal aggregate structures.Whar’s more,the mesomer（IV-5-R,S）and racemate（IV-5-rac）showed better OFET performance than the optically pure compounds,with hole mobility of 0.074 cm2·V-1·s-1 and 0.075 cm2·V-1·s-1.The result will bring out a design thinking for developing naphthalimide-based organic functional molecules.更多还原