介观组装电荷存储功能的有机纳晶及工艺可控晶体管存储器制备

The poor repeatability of solution-processed technique during the synthesis of organic thin film devices leads to the instability of device performance. Strategies based on the hierarchical control are supposed to address this problem. Here we focus on the organic semiconductor moleculars as the charge-trapping layer of the organic field-effect transistor memories. A three-level controlled technology will be involved in terms of molecular design, controlled crystallization and mesoscopic assembly. Manipulating the mesoscopic assembly of organic nanocrystal in solution is the crucial procedure. A well-organized platform for the preparation of charge-trapping layer with molecule-nanostructure-mesoscopic assembly three-level orderly will be fabricated. By comparing our samples with the charge-trapping layer fabricated by vacuum thermal evaporation or spin-coating method, we investigate the relationship between nano-effect/meso-scale effect and electron behavior/memory performances, such as memory window, retention time and program/erase cycles. The above study will facilitate the precisely-controlled solution-processed techniques for the synthesis of organic field-effect transistor memories with stable device performance.

目前湿法加工有机薄膜器件存在的主要问题在于其生产过程的不可重复性导致器件性能的不稳定。分级可控策略有望成为解决有机薄膜器件工艺问题的重要途径。本项目以有机晶体管存储器的电荷存储层为研究对象，以有机半导体小分子作为电荷存储材料，通过分子设计、结晶控制、介观组装这三个自下而上的层次展开可控工艺的研究，重点在于调控有机纳晶的溶液法介观排列，最终建立一个分子-纳米-介观三层次有序的电荷存储层薄膜制备平台。通过和蒸镀或旋涂的薄膜电荷存储层进行对比，揭示深层次纳米效应及介观效应对电荷行为、存储性能如存储窗口、维持时间、读写擦循环次数的影响，实现性能稳定的有机晶体管存储器，为建立精准可控的湿法加工工艺提供参考与借鉴。

半导体材料的凝聚态有序性是影响其光电性能的主要因素。本项目围绕芴基位阻型半导体小分子的结构设计、超分子组装纳晶、纳米排列薄膜、器件光电性质研究展开工作，提出了分子吸斥协同理论从而指导位阻型分子设计得到相应的纳晶形貌，发现了形成二维纳米结构的普适性分子设计策略，发展了包括滴涂、旋涂、狭缝涂布等一系列溶液法制备薄膜的方法，获得了具有多阶非易失性存储性能与独特的光控双极性稳定高效有机场效应晶体管存储器及全溶液法制备的有机太阳能电池器件。相关成果已经发表包括Small，Nanoscale，Cryst. Growth Des.等SCI期刊论文12篇，申请发明专利10项，培养博士毕业生2名、硕士毕业生1名。