A Single Polyaniline Nanofiber Field Effect Transistor and Its Gas Sensing Mechanisms

A single polyaniline nanofiber field effect transistor (FET) gas sensor fabricated by means of electrospinning was investigated to understand its sensing mechanisms and optimize its performance. We studied the morphology, field effect characteristics and gas sensitivity of conductive nanofibers. The fibers showed Schottky and Ohmic contacts based on different electrode materials. Higher applied gate voltage contributes to an increase in gas sensitivity. The nanofiber transistor showed a 7% reversible resistance change to 1 ppm NH(3) with 10 V gate voltage. The FET characteristics of the sensor when exposed to different gas concentrations indicate that adsorption of NH(3) molecules reduces the carrier mobility in the polyaniline nanofiber. As such, nanofiber-based sensors could be promising for environmental and industrial applications.