碳纳米管介电阻挡器件的电离与气敏特性

项目名称： 碳纳米管介电阻挡器件的电离与气敏特性

项目编号： No.60871032

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 徐东

作者单位： 上海交通大学

项目金额： 30万元

中文摘要： 利用一维纳米材料电场增强效应和介质电荷场对气体离化的限制效应，研究了一种新型的碳纳米管介电阻挡放电（DBD）器件及其电离和气敏特性，以解决此类传感器存在的高电压驱动和热不稳定性问题。设计了一种结构简洁、便于制备、有利于气体交换的对侧电极结构，运用微机械加工技术制备了微间隙三维电极，通过电泳方法在电极表面定域沉积碳纳米管，解决了大面积制备和微纳工艺兼容问题。研究了薄膜及电化学共沉积技术，形成多种具有微纳效应的DBD器件。器件在大气条件下具有明显的电场增强效应和良好的离化抑制效应，以及低功耗和对气体快速响应特性，离化阈值电压和电流抑制电压均低于10V，提高了器件稳定性和工作寿命。无机和有机介质薄膜均可获得DBD效应，无机介质的稳定性要优于有机介质。氧化镁材料具有较好的二次电子发射能力，在较低的离化阈值下得到较大的离化电流。研究了器件的交流DBD特性，获得了稳定离化的控制参数。器件离化阈值和电流幅值对气体浓度和种类均具有敏感性，不同气体的离化阈值电压与离化电流幅值有对应关系，两者结合有利于提高检测结果的准确性。设计、研发了针对人类呼吸的检测系统，验证了器件应用的有效性。

中文关键词： 碳纳米管；微纳技术；介质阻挡放电；低温等离子体；气体传感器

英文摘要： The ionization behaviors and gas-sensitive properties of dielectric barrier discharge (DBD) device based on carbon nanotubes were studied. By utilizing one-dimensional nanomaterial’ enhance effect of electric field and charge accumulates effect in dielectric structure, the device can be used to solve some problem such as the high-voltage operation and thermal instability. We have designed an innovative opposite-sidewall electrode structure, which advantages of simple structure, easy fabrication and contribute to gas exchange. Three-dimensional micro-gap electrode was realized using micro-machining technology, the carbon nanotubes was localized deposition on electrode surface by electrophoresis，which solve a large area preparation and micro-nano technology compatibility issues. The film and electrochemical co-deposition technique was studied and several type of micro-nano DBD devices was fabricated. The results showed that the ionization enhancement significantly in the initial gas ionization stages and that ionization was suppressed when the ionization current rapid growth, the voltage of ignition ionization and suppression were both lower than 10V. The operations of such device are characterized by low power consumption, fast response and short recover time, high reliability and long lifetime. The inorganic and organic dielectric films both can be obtained DBD effect; the stability of inorganic dielectric is superior to organic. Magnesium oxide has a good ability of secondary electron emission to obtained higher ionization current at low threshold voltage. The characteristics of DBD device under AC condition were studied and the control parameters for stabilization ionization were obtained. The test result demonstrated that the voltage of Ionization threshold and the current amplitude could both identify gases concentration and type. The threshold voltage and current amplitude of gas ionization have the corresponding relation; both combined will help improve the accuracy of test results. A human respiratory detection system was designed and developed for explore the effectiveness of the DBD device application.

英文关键词： carbon nanotubes;micro/nano technology;dielectric barrier discharge;low temperature plasma;gas sensors