Disconnect armchair carbon nanotube as rectifier predicted by first-principles study

• We constructed a one-dimensional rectifier using carbon nanotube.
• The rectification ration increases as the diameter of carbon nanotube increases.
• Quantum size effect enhance performance and decrease power depletion for molecular electronics.

For electronics devices based on carbon nanotube, we propose that the localization of the density of the states can enhance the rectification effect. The proposal is confirmed according to the first-principles study of the transport characteristics of several disconnected armchair nanotubes where only one side of armchair edge is hydrogenated. We find that the rectification effect increases as the diameter of armchair carbon nanotube and has no trend of decrease, which originates from the localization of the density of states of the pristine armchair edge. Our investigations indicate that the quantum size effect is helpful for molecular or nano-scale electronics devices.