用于多种痕量气体并行检测的碳纳米管场效应晶体管传感器阵列研究

气体传感器在空气污染治理方面占有重要的战略地位。在复杂气体环境中，电阻型气体传感器对多种气体的交叉敏感性是气体检测领域亟待解决的瓶颈问题，其主要障碍在于器件仅依托单一参数评价选择特性、灵敏特性等多种气敏性能。针对如何利用具有丰富器件参数的场效应晶体管(FET)阵列实现“痕量气体浓度检测、混合气体种类识别”两个关键科学问题，本项目选择以半导体碳纳米管薄膜为沟道的高跨导FET为研究对象，设计栅极敏感型碳基FET气体传感器，揭示碳基FET器件对痕量气体微弱信号的增益机理，拓展气体传感器的检测下限。在此基础上，进一步开展器件阵列结构设计，发展特征信号提取与并行检测模式，从材料特性、器件结构、阵列形式等方面，重点研究FET阵列对气敏性能的多参数分类关联，明晰阵列结构在混合气体种类识别中的工作机理，实现混合气体中各痕量气体的精准识别，为更有针对性地发展多种痕量气体并行检测技术提供有效的思想方法与手段。

Gas sensors play an important strategic role in the field of air pollution control. In the complex gas environment, the crossing sensitivity of resistive gas sensors to various gases is a bottleneck problem to be solved in the field of gas detection, and the main obstacle is that there just only single parameter of sensor is used to evaluate the selectivity, sensitivity and other gas sensing properties. The project aims at addressing some most critical issues in multiple trace-gases detection, that is, how to realize the two key scientific problems of "trace-gas concentration detection and gas species identification in gas mixture" by means of the field effect transistor (FET) array with abundant device parameters. In this project, the high transconductance FET using semiconducting carbon nanotube thin film as channel is selected as the object to fabricate the gate-sensing type carbon-based FET gas sensor. The gain mechanism of carbon based FET device for the weak response to trace-gas is revealed to expand the detection limit of gas sensor. On this basis, we will further design the array device structure and develop the corresponding feature signal extraction and parallel detection mode. A multi-parameter classification correlation mechanism between FET array devices and gas sensing properties is developed from the aspects of material characteristics, device structure and array form. At last, the working principle of array structure in species identification of the gas mixture is clarified to realize the accurate recognition of various trace-gas in gas mixture, which provides effective thoughtway and method for developing simultaneous detection technology of multiple trace gases.