Correlation Between On/Off Ratio and Electron Traps in Hole-Only Carbon-Nanotube-Enabled Vertical Field Effect Transistors

Abstract

Single wall carbon nanotube enabled vertical field effect transistors (VFETs) are studied and the dependence of the on/off ratio on the relative number of electron traps is investigated. Current versus voltage measurements on several VFETs with varying interfacial trap densities in the vicinity of the nanotube network/polymer active layer junction are taken. It is found that the on/off ratio of the VFET changes from 1600 to 20 for typical operational currents as the onset gate voltage in the off-to-on transfer curve shifts from 94 V to 72 V. Such a strong dependence on trapped charge motivates future work to uncover the mechanism of charge trapping.