Schottky barrier formation at metal electrodes and semiconducting carbon nanotubes

Schottky barrier (SB) formation at the contact interface between metal and semiconducting carbon nanotubes (CNTs) is of great importance in determining the transport characteristics of a CNT field effect transistor. In this paper, we studied the SB height (SBH) between different metals and CNT contacts using first-principles calculation. A method to calculate SBH is proposed based on the interface dipole effect, which will induce an electrical potential variation at the metal and CNT interface. The SBH of a metal and CNT contact could then be determined by the work function difference between the metal and CNT and the electrical potential variation. We extensively investigated different contacts between Sc, Al, Pd, (8,0) CNT, and (11,0) CNT. The calculated SBHs for these contacts are all in good agreement with experimental results.