Impacts of image force on the Schottky barrier height at metal-carbon nanotube contacts

Abstract

By using first-principles calculations and classical image force model, we studied the image force induced Schottky barrier (SB) height reduction in carbon nanotube (CNT)-metal contact. A low dielectric constant leads to a stronger band bending and therefore strongly reduces the SB height. This reduction depends on carrier concentration and CNT diameter. For CNT with carrier concentration of 1020 cm−3, the reduction in SB height caused by image force is up to 0.7 eV when CNT diameter is less than 20 Å. Our results demonstrate that image force induced SB height reduction is important for the design of CNT-based nanoelectronic devices.