The effect of the field emission on CNTs for N2 detection

Carbon nanotubes (CNTs) were used as a field emitter and N2 detector under high vacuum measurement at room temperature. First, the CNTs detected different N2 concentrations by playing as a resistance sensor. It was found that the sensitivity was about 11% when exposed to 500 Torr N2 concentration. Then, the CNTs underwent some field emission manipulations for the following times: 1 h, 2 h and 3 h. After such field emission treatment, the CNTs went through the same procedure for N2 detection and showed a sensitivity of nearly 30% under 500 Torr N2 concentration. It was suggested that due to the field emission, the CNTs provided more adsorbing sites for N2, as shown by FE-SEM and Raman.