反应型液晶半导体的合成、性质及其有机场效应晶体管性能

Molecules close and orderly packing mode is benefit to obtain high carrier mobilities. Under the mesomorphic temperatures, liquid crystal semiconductor is a quasi-fluid and characterized of the self-assembling property to form a highly long-range ordered molecular stack,showing a crystal-like structure. It is considered to be a potential high-quality organic semiconductor.The project designs and synthesizes a new series of small molecular reactive mesogens.The molecule is characterized of 1,4-diketo-3,6-dithienylpyrrolo[3,4-c]pyrrole(DPP) as the aromatic core and diacetylenes as the photochemical reactive groups. An attempting way to prepare highly orientated thin solid film is to lock-in the molecular long-range ordered packing mode by photo-crosslinking/polymerization. The thin film are used as an organic semiconductor layer to prepare the organic field-effect transistors and their properties were studied. Comprehensive are carried on molecular design and systhesis, molecular self-assembly property, film formation and morphology, device fabrication and performance and the scientific issues about the relationship of the molecular structure, molecule packing mode in mesophase phase the film morphology and devices carrier transport performance are explored.The goals are to obtain reaction mesogen semiconductor with good comprehensive performance and sum up the law between molecular microscopic arrangement and material performance.

分子紧密有序堆积有利于获得高的载流子迁移率。液晶半导体在介晶温度下为准流体态，分子具有自组装特性，形成高度长程有序的分子排列，表现出类似晶体的结构特性，被认为是一种有潜力的高质量有机半导体。本项目设计合成一类新型的小分子反应型液晶，以3,6-二噻吩-吡咯并吡咯二酮为芳香核，以联二乙炔基作为光化学反应基团，尝试在分子的介晶相态温度下发生光交联/聚合反应"锁定"分子的长程有序排列，制备高取向的固体薄膜，并作为有机半导体层制备有机场效应晶体管，研究其性能。本项目对分子的设计合成、分子自组装特性、薄膜的生成和形貌、器件制备和性能进行综合研究，探索分子结构、介晶相态分子堆积形态、薄膜形貌与器件载流子传输性能关系的科学问题；目标是获得综合性能优良的反应型液晶半导体材料，并总结分子微观排列与材料性能规律性的认识。

本项目围绕反应性有机半导体材料及其光电性质开展研究工作，执行期间取得的主要进展如下：设计并成功合成了系列端基含联[n]炔基的吡咯并吡咯二酮化合物，优化了合成方法，能够较高产率的得到目标产物。对合成化合物的性质及其器件进行了较详细的研究，分子表现出良好的溶解性、自组装特性和光热反应性，其场效应晶体管表现出空穴传输性能，具有在有机光电器件方面的潜在应用前景。设计并成功合成了系列偶氮甲碱桥连噻吩化合物，方法简单且产率高易于后续提纯，通过改变噻吩上取代基的类别改变分子的热反应性和稳定性。设计并成功合成了系列含香豆素光敏基团聚合物，制备了液晶小分子掺杂光功能性聚合物体系，并对其液晶性能、热性能做出评价，并通过相应评价方式对其取向性能做了研究，反应性液晶半导体分子的光化学诱导取向的热增幅效率达到两个数量级。.项目执行期间发表期刊论文2篇，会议论文2篇，申请国内专利3项。后续研究论文正在撰写和投稿过程中。