Modelling of carbon nanotube film based temperature sensor: thermal emission and gas discharge

Abstract

The carbon nanotube (CNT) film based ionized temperature sensor is sensitive to gas temperature, and shows good sensitivity compared with other temperature sensors. But it is still unclear about the effect of CNT film on thermal emission and gas discharge at different temperatures. In this article, we established a gas discharge model of the CNT film temperature sensor. Field assisted thermal emission is simulated at the tip of CNTs by analysing the field enhancement effect and effective work function. Ionization collision, excitation, recombination collision, Penning ionization and quenching of argon are considered in order to obtain the interaction of various particles at different temperature. The current density-temperature characteristic of the temperature sensor was obtained at 24–80 V. The increase of the working voltage is helpful to improve the output current and sensitivity of the temperature sensor. Response time of the sensor will not change in the temperature range of 293–373 K. However, the change of temperature will affect the current density, secondary electron emission and reaction rate. In addition, the sensor has different temperature sensitivity in argon and helium. The above simulation results are helpful to understand the role of CNT film and temperature sensitivity of the ionized sensor. It can also be used to study and improve the sensitivity of this type of sensor.