The effect of carbon nanotube tip functionalization on electronic tunneling

Abstract

Modification of carbon nanotubes by doping and functionalization is widely used to control individual nanotubes’ properties and interaction with surrounding media such as polymer matrix. As it is known from experiments and theoretical calculations, sidewall modification can increase nanotube-matrix interaction but reduce nanotube conductivity significantly. The reported work investigates the effect of doping with boron and nitrogen and fictionalization with –COOH groups on carbon nanotube tip electrical properties. It is shown using density functional calculations of several nanotube tip models that doping and functionation can modify local density of electronic states thus boosting or decreasing tunneling currents between carbon nanotubes while having negligible effect on individual nanotube conductivity itself. Thus a possibility is opened to increase electrical characteristics of CNT based materials and devices by tip region modification and selecting appropriate type and amount of dopant/chemical group.