新型有机半导体材料的设计合成及在光电器件中的应用

The application of organic semiconductors in organic field-effect transistors (OFETs) or organic photovoltaic cells (OPVs) etc. still faces kinds of challenges, although they have attracted extensive attention due to their flexibility, colorful property, ease to be modified and solution-processibility to lower the cost etc. Taking OFETs as example, although the highest mobility of organic semiconductors has reached 40 cm2/Vs, there are still some problems to be solved: the mobility and stability of organic semiconductors are still much lower than their inorganic counterparts; the structure-property relationship is still not clear; the charge transport mechanism is still not well defined; and the fabrication process are still not mature (which result in high cost)..In this proposal, we will focus on the organic semiconductors, the most crucial part of organic devices: A series of novel semiconductors are designed and synthesized. The most important advantage of this series of semiconductors is that it is believed that the intermolecular interactions in two orientations at least might be strengthened, which would facilitate the charge transport to achieve high performance. In the following, we will fabricate the thin-film and single crystal transistors based on this series of semiconductors to obtain devices with high performance and reveal the relationship among the chemical structures, the arrangements and the properties, which are expected to helpful in our organic optoelectronic industry.

有机半导体材料因其柔性、多彩性、易修饰改性、可溶液加工以降低成本等方面无与伦比的优点吸引了广泛的兴趣。但有机半导体材料在场效应晶体管、太阳能电池等领域还存在各种不足。以有机场效应晶体管为例，尽管目前最高的场效应性能已经可达40 cm2/Vs，但是有机场效应晶体管仍然存在着迁移率较低（相对于无机材料）、稳定性较低、结构与性能之间关系不清晰、电荷传输机理不明确以及器件制备工艺不成熟等方面的问题和挑战。针对此种问题，申请者从有机器件的最核心半导体材料出发，设计和合成一系列新型结构的半导体材料，这种结构的半导体材料，有希望至少从两个取向上增强分子间作用力，有望获得较高的场效应性能。将该系列半导体材料应用于薄膜场效应晶体管，实现高性能的有机薄膜晶体管。进而将其应用于单晶场效应晶体管，探索其化学结构、堆积结构以及性能的关系。有望在高性能器件、结构与性能的关系以及器件制备工艺等方面取得新进展。

本项目致力于有机共轭材料的分子设计、自组装合成及其应用研究。申请人研究了基于溶液法的难溶化合物金属酞菁的可控生长，探讨了溶液法在有机半导体材料晶体生长及器件制备上的优势和特点，为合成具有热力学不稳定相的有机半导体大单晶提供了新的途径，对于棘手难溶化合物的处理具有重要的指导意义，对有机半导体材料的发展意义重大。与此同时，申请人还通过分子设计，针对性的研究了硫原子朝外对有机半导体场效应性能的影响，为提高有机半导体材料的场效应性能提供指导。此外，申请人还通过分子设计，研究了材料共轭体系与钠离子电池快速充放电性能之间的关系；提出扩大材料的共轭体系有利于提高材料的快速充放电性能。还研究了分子设计和电化学窗口调控方面对于钠离子电池中的长期循环性的影响，为提高有机钠离子电池的性能提供新思路。上述相关研究成果分别发表在国际权威学术期刊Chemistry-A European Journal，Advanced Functional Materials和Journal of American Chemical Society上。