Modeling of carbon nanotube Schottky barrier modulation under oxidizing conditions
نویسنده
چکیده
A model is proposed for the previously reported lower Schottky barrier FBh for hole transport in air than in vacuum at a junction between the metallic electrode and semiconducting carbon nanotube ~CNT!. We consider the electrostatics in a transition region between the electrode and CNT in the presence or absence of oxygen molecules ~air or vacuum!, where an appreciable potential drop occurs. The role of oxygen molecules is to increase this potential drop with a negative oxygen charge, leading to lower FBh in air. The Schottky barrier modulation is large when a CNT depletion mode is involved, while the modulation is negligible when a CNT accumulation mode is involved. The mechanism prevails in both pand n-CNT’s, and the model consistently explains the key experimental findings.
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