Study Of Improvement Of Performance Of Field Effect Transisitor Sensors Based On Single-walled Carbon Nanotubes

Single-walled carbon nanotubes( SWCNTs) are nearly ideal one-dimensional(1D) molecule wires. It has many unique features, such as large specific surface area, ballistic transport properties, high field-effect mobility and good performance of gas adsorption and so on. In this paper, we made the single-walled carbon nanotubes-based field effect transistor sensors with good performance of high sensitivity, short response time and convenience. As the method, we used MEMS technology to fabricate the SWCNTs-based field effect transistor sensors. And we used self-assembly technique to prepare the SWCNTs-network. Combined with lift-off process, the electrodes can be deposited on the surface of SWCNTs-network, and a good ohmic electrical contact can be assured. This method is simple, high yield and can achieve wafer-scale production, expecting to use in industries. And then we used it to detect dimethyl methylphosphonate(DMMP) which is the gas stimulant of chemical warfare agent sarin. At last, we used UV radiation to etch and(or converse) the metallic single-walled carbon nanotubes(m-SWCNTs) from the networks, increasing the proportion of semiconducting single-walled carbon nanotubes(s-SWCNTs), and ultimately increased the channel current on/off ratio(Ion/Ioff) and improved the sensor’s performance. In addition, we also tried to detect Trinitrotoluene(TNT) explosives in water phase through amino function on SWCNTs, and got the initial achievements. In conclusion, the results we got from this study show that both UV-radiation and amino-function are able to improve the performance of the SWCNTs-based field-effect transistor sensors.