Simulation of ambipolar-to-unipolar conversion of carbon nanotube based field effect transistors

Using an oxide right prism attached to the drain electrode of carbon nanotube based field effect transistors (CNTFETs), we have obtained asymmetric transfer characteristics of the CNTFETs based on semiclassical simulation. The calculated results suggest that the slope of the prism and the electrode thickness play important roles in the transfer characteristics of such CNTFETs. Through optimizing them, we can convert the performance of the CNTFETs from ambipolar characteristics to unipolar (p-type or n-type) behaviour with a significant drop in the OFF current or an increase in the ON/OFF current ratio.