有机半导体径向异质结一维纳米材料的制备及其光电特性研究

One-dimensional (1D) organic semiconductor nanomaterials have brilliant and promising applications in nanoscale optoelectronic devices benefitted from their unique characteristics. Currently, most of the research works concerning about 1D organic semiconductor nanomaterials are focused on the homogeneous structure of single-component compounds. However, charge separation of the excitons formed in homogeneous 1D organic semiconductor nanomaterials under light radiation is not effective in most cases. As a result, the optoelectronic properties of these nanomaterials are usually not satisfying. To solve this problem, we plan to synthesize some organic electron donors and acceptors with specific molecular structures which can be utilized to fabricate 1D organic semiconductor nanomaterial with a radial heterojunction through intermolecular reactions or interactions between electron donors and acceptors. Such a heterojunction comprises electron donor, nanoscale insulating separator, and electron acceptor. On the one hand, this kind of heterojunction can increase the contact interface between electron donors and acceptors; on the other hand, it can suppress the back-transfer process of electrons at the contact interface. So the optoelectronic properties of 1D nanomaterials can be improved. In this project, the optoelectronic characteristics of 1D nanomaterial with this radial heterojunction will be studied. In addition, we will investigate factors which may influence the morphology of 1D nanomaterial with this kind of radial heterojunction and find approaches to tune its morphology. Finally, we will explore the structure-property relationships between radial-heterojunction 1D organic semiconductor nanomaterials and organic optoelectronic devices.

一维有机半导体纳米材料由于具有许多独特的光电特性因而在纳米光电器件领域有着美好的应用前景。目前，绝大多数有关一维有机半导体纳米材料的研究工作是围绕着单一化合物生长得到的同质结构开展的。然而，同质一维有机半导体纳米材料在光照下产生的激子一般不容易发生有效的电荷分离，导致其光电活性通常较差。为了解决此问题，我们计划合成具有特定结构的有机电子给/受体材料，通过其分子间的反应或相互作用，制备出具有径向异质结结构的一维有机半导体纳米材料。此异质结由电子给体-纳米级绝缘间隔-电子受体所组成，一方面可以增大电子给/受体的接触界面，另一方面可以抑制界面处电子的回传过程，从而改善纳米材料的光电活性。研究此种径向异质结一维纳米结构的光电性质。通过调查影响此种径向异质结一维纳米结构形貌的因素，了解并掌握调控其形貌的手段，探索径向异质结一维有机半导体纳米材料的组成及结构与有机光电器件性能之间的关系。

一维有机半导体微/纳米材料在光电器件领域有着美好的应用前景，但是绝大多数有关一维有机半导体微/纳米材料的研究工作是围绕着单一化合物生长得到的同质结构开展的。同质一维有机半导体微/纳米材料在光照下产生的激子一般不容易发生有效的电荷分离，导致其光电活性通常较差。为了解决此问题，本项目从有机半导体材料的设计与合成、径向异质结有机一维微/纳米材料的构建及形貌调控、有机径向异质结微/纳米线光电器件的制备及性能研究等方面入手，围绕制备出具有径向异质结结构的一维有机半导体微/纳材料从而改善其光电活性这个目标，开展了一系列研究工作。主要研究结果包括：1）设计合成了吡嗪并二噻吩类有机半导体材料，改善了电子给体材料在光照下的稳定性；2）通过溶液法制备出了小分子@小分子、小分子@聚合物、小分子@石墨烯、三元同轴等多种体系的径向异质结一维有机微/纳米材料；3）基于所制备的径向异质结一维有机微/纳米材料构建出了光导器件和光敏二极管等光电元件，并研究了其光电特性，探讨了其工作机理。本项目为改善一维有机半导体微/纳材料的光电性能及开发其潜在的应用提供了借鉴意义。