Strain induced modulation of switching behavior in carbon nanotube tunneling field effect transistors

We study numerically the effect of axial strain on the band structure of semiconducting carbon nanotubes (CNTs) and the transport characteristics of CNT based band-to-band tunneling field effect transistors (CNT-TFETs). By making use of empirical tight-binding method and the non-equilibrium Green´s function formalism, we found that applying the axial tensile strain can dramatically suppresses the off-leakage current in CNT-TFETs, and makes the subthreshold swing steeper. Such improvement of the device performance can be understood qualitatively to be caused by the band gap modulation in the CNT channel region.