高迁移率小分子/高分子共混半导体材料体系的研究

Further enhancing mobility and avoiding gate voltage-dependence of mobility are two key issues which have to be addressed for the field of organic semiconductors and organic thin-film transistors (OTFTs). The condensed state structure of organic semiconductors is one of the most important factors influencing OTFT performance. Blending organic small molecule semiconductors with conjugated polymers has proven to be able to overcome the issues, i.e., poor film forming capability of the former and low film order as well as difficult modulation of film microstructures of the latter, and hence allowing the fabrication of OTFTs that outperforme those based on individual component. Thereby in the current project, we propose a new way to develop high performance organic semiconductor systems, that is, to blend high mobility small molecule or oligomer semiconductors with high mobility conjugated polymers featured by different crystallization-characteristics. Upon systematic study of formulation principle of the blends and modulation method of condensed state structures, the relationship between molecular structures as well as blend ratios, condensed state structures and OTFT performance will be established. By combining the advantages of both components, i.e., the high mobility of small molecules and excellent mechanical property of conjugated polymers, we aim to develop new solution processed blend material systems with OTFT mobility >15 cm2/V•s, and meanwhile independent on gate voltage. We hope that this study can provide potential high mobility material candidates for the development of high performance printing OTFTs in China.

进一步提高迁移率和消除迁移率的栅压依赖性是目前有机半导体材料及有机薄膜晶体管（OTFT）研究领域亟待解决的问题。鉴于聚集态结构是影响OTFT性能的关键因素之一，而将小分子半导体材料与高分子半导体材料共混能够克服前者成膜性差、后者薄膜有序度低和聚集态结构难以调控的问题，获得OTFT性能优于单一组分的材料体系，本项目提出选取具有高迁移率特征的小分子半导体材料和具有不同结晶性质的高分子半导体材料，发展高迁移率小分子/高分子共混半导体材料新体系的研究思路。在系统研究共混组分的结构匹配原则以及聚集态结构调控方法、建立分子结构/共混比例-聚集态结构-OTFT性能关系的基础上，综合利用小分子半导体材料结晶度高和高分子半导体成膜性好的优点，发展OTFT迁移率>15 cm2/V•s且无栅压依赖性的溶液加工型高迁移率半导体材料新体系，为我国高性能印刷OTFT的发展提供材料基础。

如何制备可溶液加工、具有可信高迁移率有机薄膜晶体管（OTFT）是有机电子领域亟待解决的问题。本项目将小分子的高迁移率与聚合物的溶液加工性能优势结合，构筑小分子/聚合物共混体系，通过薄膜聚集态调控，获得综合性能优异的OTFT。主要结果包括：.（1）将苯并噻吩并苯并噻吩（BTBT）衍生物小分子与具有不同结晶性质的共轭聚合物共混构筑p-型共混体系，将吡咯并吡咯二酮（DPP）衍生物小分子分别与共轭聚合物、绝缘聚合物共混构筑n-型共混体系，通过研究以上共混体系，初步掌握了小分子/聚合物共混半导体材料的组分匹配原则，建立了分子结构/共混比例-聚集态结构-OTFT 性能关系；.（2）初步掌握相关共混体系的聚集态结构调控方法，结合分子掺杂、界面修饰等器件工程手段，获得了空气稳定、可溶液加工的高迁移率p-型和n-型OTFT，为进一步开发性能可靠的可印刷OTFT及相关有机电路提供了材料基础。.在Macromolecules、Adv. Sci.、J. Mater. Chem. C、Chin. J. Chinese上共发表学术论文4篇，培养博士生2名、硕士生3名。