Carbon nanotubes: Inter-molecular logic circuit #2

Fabrication of a voltage inverter (“NOT” logic gate ) using two nanotube field-effect transistors. Initially the two nanotube transistors are p-type. One of the them is protected by an insulating layer, the other is not. (a) Placing the nanotubes in a vacuum converts the p-type nanotube transistors to n-type. (b) The two CNTFETs are then exposed to oxygen (10-3 Torr of oxygen for 3 minutes). The unprotected n-type nanotube transistor (black curve) converts back to the original p-type, while the protected nanotube transistor (red curve) remains n-type. (c) The two complementary (p-type and n-type) carbon nanotube transistors are wired as shown in the schematic. (d) characteristics of the resulting inter-molecular inverter (V=1.5 V).