Is Corbon a semiconductor

Smallest tubes for maximum performance

For the first time, researchers have also succeeded in using carbon nanotubes for the construction of power semiconductors. This is considered a breakthrough for nanotechnology, as scientists have previously assumed that the tiny components on an atomic scale are not suitable for the high voltages and currents in power semiconductors. This means that power switches could one day be made much smaller and cheaper than before.

Nanotubes are tiny tubes made of carbon atoms with a diameter of a millionth of a millimeter. A person's hair is about 100,000 times thicker. Transistors for computer chips have already been made with these tiny tubes in research laboratories to store and process information. But only small electrical voltages and currents are involved. In the case of power transistors, on the other hand - as used in electric motors, lamps or power supplies - the voltage and current are more than a thousand times greater. They serve as switches that are primarily concerned with minimizing energy losses or avoiding mechanical components. So far, power semiconductors have mainly been made from silicon, but this is relatively complicated and expensive.

With their first experimental setup, researchers from the semiconductor manufacturer Infineon demonstrated that carbon nanotubes also work in power transistors. Prerequisite: Hundreds or thousands of them must be packed together in parallel. The Infineon prototype switches light-emitting diodes and small electric motors at a voltage of 2.5 volts. It consists of around 300 nanotubes arranged in parallel. The main advantages of the new power transistors are a significantly simpler manufacturing process, higher switching speed, low heat generation and high current densities, which the tightly packed carbon tubes can withstand. The power transistors made from carbon nanotubes are still at the basic research stage. It is still unclear when they can be commercially produced in large numbers.

(ots - Infineon Technologies AG, February 24, 2004 - AHE)

February 24, 2004