碳纳米管场效应型DMMP气敏传感器研究

基于单壁碳纳米管(SWCNT)的场效应气体传感器由于具有传感性能好、体积小、室温操作和加偏压自我解吸附等优良性能,有着广泛的应用前景。利用单壁碳纳米管自组装技术在SiO2/Si基底上制备均匀分布的SWCNT薄膜,将其作为沟道制作了具有灵敏开关特性的场效应晶体管(FET),该FET器件的开关比达到105。将此FET器件作为气体传感芯片用于甲基膦酸二甲酯(DMMP)气体分子的检测。结果显示,当通入DMMP气体时,器件的阈值电压向负栅电压方向移动。当DMMP体积分数为5×10-6,栅压为-10 V时,器件的灵敏度达到32%,响应时间为300 s。在15 V的栅压下器件能够很快地实现气体解吸附。

Study on Carbon Nanotubes Based Field-Effect DMMP Gas Sensors

Field-effect gas sensors based on single walled carbon nanotubes(SWCNTs) have shown a promising application,due to their excellent properties,such as high sensitivity,small size,room temperature operation,and self-desorption by gate bias.The uniform distributed SWCNT film was prepared by SWCNT self-assembly technology on the SiO2/Si substrate.The field-effect transistor(FET)with sensitive switch characteristics was fabricated with the SWCNT film as the channel.The on/off ratio of the FET device reaches 105.The FET device used as the gas sensor chip to detect the gas molecules of dimethyl methyl phosphonate(DMMP).The result shows that the threshold voltage of the device moves toward the negative gate voltage direction when the DMMP gas is flowed.With the DMMP volume fraction of 5×10-6 and gate voltage of-10 V,the device sensitivity and response time are 32% and 300 s,respectively.The device is able to realize the gas desorption quickly at the gate voltage of 15 V.