Electrical Heating Process for p-Type to n-Type Conversion of Carbon Nanotube Field Effect Transistors

A new electrical heating process was proposed which converts carbon nanotubes from p-type to n-type by desorption of oxygen molecules around the carbon nanotubes. By applying a large voltage of ∼40 V between the source and drain electrodes in vacuum, a large drain current of ∼20 µA flows the carbon nanotube channel and heats it, which cause oxygen molecules to desorb from the surface of the carbon nanotube. After applying electrical heating, the carbon nanotube field effect transistors clearly showed n-type properties. Moreover, they recovered p-type properties when exposed to ambient air.