基于聚合物纳米线的高性能近红外有机光晶体管的研究

Near-infrared photodetectors, which are widely used in night vision, artificial vision, and optical communication, are important high value-added fields in the semiconductor industry, Compared to organic semiconductor, the fabrication of conventional inorganic semiconductor photodetectors requires high temperature deposition on a substrate and a complicated processing. Organic semiconductors with the advantages of low temperature deposition and mechanical flexibility have been researched by academia and industry for the purpose of construct large-area, low-cost flexible optoelectronic devices. The organic phototransistors (OPT) can integrate functions such as light detection, switching and signal amplification into one device to achieve high photo-responsivity and low noise signal. However, most organic semiconductors are wide-bandgap materials, so there are few studies on near-infrared organic phototransistors. We expect to prepare narrow-bandgap polymer nanowires (arrays) by solution templateless assembly or template technique, and characterize their supramolecular structure and packing mode; select appropriate device structures or optimize device interfaces (interface modification, energy Level engineering, etc.) to achieve high performance near-infrared phototransistors based on polymer nanowires. More importantly, the deep understanding of the relationship between molecular structures，nanowire packing and device performance based on the experimental and theoretical study will give insight into the development of high performance near-infrared organic phototransistors.

近红外光探测器是半导体行业中重要的高附加值领域，广泛应用于夜视仪，人工视觉，光纤通讯等各个方面。然而，传统无机半导体器件的制备需要在衬底上高温沉积，处理过程复杂。有机半导体具有低温沉积和机械柔性的优势，因此可以构筑大面积、低成本的柔性光电器件，引起了学术界和工业界极大的研究兴趣。其中，有机光晶体管可以将光检测、开关和信号放大等功能集成于一个元器件中，实现高光响应度和低噪音信号。然而，有机半导体大多是宽带隙材料，所以近红外有机光晶体管研究较少。我们拟将窄带隙的聚合物半导体通过溶液自组装法或模板法制备聚合物纳米线(阵列)，并对其结构和堆积方式进行表征；选择合适的器件结构或优化器件界面(界面修饰，能级调节等)以实现其对近红外光的高灵敏度响应，设计合成高性能的聚合物纳米线近红外有机光晶体管。通过对分子结构—纳米线堆积—器件性能关系的研究，为近红外有机光探测器的研究提供实验及理论指导。

窄带隙的聚合物或非富勒烯小分子具备近红外吸收的特性，同时，有机材料具有低温沉积和机械柔性的优势。因此，可用于构筑大面积、低成本的柔性光电器件。本项目围绕高性能的有机聚合物或小分子系统深入的分子设计与制备工作，制备了系列的高性能有机共轭材料，包括非富勒烯类小分子受体共轭材料、双缆型聚合物材料，实现了宽的吸收光谱、能级可调以及优异的光电转换性能。同时，构筑了高性能的有机半导体单晶光晶体管，获得了高于1.94/0.84 cm2/(V•s)的电子/空穴迁移率，以及103 A/W的光响应度和104的光敏度。更进一步地，我们开展了关于有机共轭聚合物的机械性能研究，并制备得到高性能、高柔性的有机光电器件。.本项目的研究结果丰富了近红外有机共轭材料的种类，为高性能有机光电器件的制备提供了借鉴。并且以此为基础，深入研究了有机材料的机械性能，发展了系列柔性光电器件，为实现高性能、柔性的有机光电器件提供了新的研究思路。