Fabrication of low-pressure field ionization gas sensor using bent carbon nanotubes

Abstract

Bent multiwall carbon nanotubes (CNTs) were grown on silicon substrate by manipulating the direction of the electric field during the growth process in the plasma enhanced chemical vapour deposition system in the presence of hydrogen and acetylene gases. Different geometries of the as-grown nanostructures were employed to fabricate a novel field ionization gas sensor. The high sensitivity of this sensor in low pressures is its main advantage in comparison with other gas sensors. Electrical characteristics of the fabricated sensor were investigated while being exposed to several gases, the results of which were compared with those of vertical CNTs-based gas sensors.