酞菁基场效应晶体管阵列的构筑及化学传感性质研究

The high performance semiconductor materials are the crucial components for the design of electronic nose and tongue of bionic systems, which are expected to have promising applications in both civil and military fields, such as food safety control, environment monitoring, anti- or counter terrorism etc. As a kind of conventional p-type semiconductor material, phthalocyanines have attracted considerable attentions due to their great potential application in organic filed effect transistors (OFET) and gas sensors. In particularly, our recent studies have revealed that p-type phthalocyanine semiconductors can be changed into n-type or even ambipolar semiconductors by changing on molecular structure. Based on this, in this project we have designed a series of p-/n-type and ambipolar phthalocyanine semiconductors for the applications in gas sensing devices. The resulted compounds are expected to have good self-assemble behavior. By means of the excellent compatibility between the different phthalocyanine materials, the molecular self-assembly can be fabricated into hierarchical structure and can be used directly in OFETs. Ultimately, the OFETs will be integrated into a gas or vapor sensor array, which will provide an extremely powerful sensing platform for electronic detection and discrimination of low concentration of volatile organic compounds (VOCs). The present study aimed at understanding the mechanism of the synergistic responses and interactions between phthalocyanine semiconductors and VOCs based on arrays of integrated OFET sensors, which will be valuable for the development of novel functional semiconductor materials and new integrated OFET based chemical sensors arrays.

高性能半导体气敏材料与集成智能传感单元是电子鼻（舌）等仿生系统研究的关键，在食品检测、环境监测、反恐防恐等民用及军事领域具有重要的应用前景。酞菁是一种传统的p型有机半导体材料，可以应用于场效应晶体管和气敏传感器中。然而我们最近的研究显示，通过对其分子结构进行修饰，可以将其变成n型甚至双极型的半导体。本课题将在这个基础上，以化学传感功能为导向，设计合成几类新型的具有优良自组装性能的p型、 n型和双极型的酞菁配合物，借助于不同酞菁材料之间优良的相容性，组装成具有多级结构的材料并直接用于场效应晶体管（FET）器件中，最终实现FET阵列的集成。研究这样的集成器件对低浓度有机挥发性气体（味）的辨识和区分能力。探讨酞菁分子材料的气敏规律性，通过"性能导向-结构调控"对酞菁分子结构及组装体的结构形貌进行优化、调控，同时对多个传感器件在集成阵列中相互协同及增效的作用机制进行系统研究。

本课题紧紧围绕具有优良自组装性能的p 型、n 型和双极型的酞菁基配合物的设计合成及其作为高性能场效应晶体管（FET）和化学传感器件的应用研究这个方向, 主要在三个方面开展了工作：一是设计合成了一系列单层、双层、三层、双核双层和双核三层酞菁/卟啉金属配合物，成功实现了通过分子设计有效调节分子的HOMO\LUMO能级，进而实现了分子半导体电荷传输性质从p-型、n-型到双极性的可控转化；二是借助π-π相互作用，范德华力，氢键等的相互协调作用，通过不同的溶剂处理方法实现了对聚集体形貌和微观结构的调控；三是通过分子结构和聚集体结构的优化得到了一批高性能场效应晶体管及高灵敏性、高选择性的室温化学传感(阵列)器件。其中通过对萘酚取代三明治酞菁铕自助装膜的二次溶剂自组装，成功得到了空气中稳定且平衡的双极场效应晶体管，其空穴和电子迁移率分别达到1.71 cm2 V-1 s-1 和1.25 cm2 V-1 s-1，开关比为106，是单一小分子半导体材料用低成本的溶剂处理方法进行器件制备，得到的最好的结果之一。为通过分子结构设计及界面组装得到更高性能的双极场效应晶体管提供了一个新的思路。四吡咯基稀土三明治配合物室温化学传感器的最低检测限(DL): H2O2为0.017μM，乙醇100 ppm、NH31 ppm、NO2 20 ppb、H2S 100 ppb，是迄今为止四吡咯基化合物化学传感器的最好结果。构筑了一个传感器阵列成功地定性和定量区分ppm级的NH3和ppb级的NO2和H2S。显示了四吡咯基稀土三明治配合物在场效应晶体管及化学传感器领域的巨大潜能。特别地，我们首次揭示了双极有机半导体气敏材料对检测物的响应模式（p-或n-型）及灵敏度的高低主要取决于更低的载流子（电子或空穴）密度和更高的电荷迁移速率，为双极半导体材料作为传感器的应用提供了理论指导。