An international team of scientists, including researchers from Japan, China, Russia, and Australia, used a unique tool they had developed and built into a typical electron microscope to create a tiny transistor 25,000 times smaller than the thickness of a human hair. The creation of this transistor, the starting material for which was a common carbon nanotube, was the result of work and research that lasted nearly five years.
“We made a very interesting fundamental discovery, we demonstrated the possibility of controlling the electronic properties of individual carbon nanotubes,” says Dmitry Golberg, professor at NUST MISIS, Russia. “The tiny carbon transistors we created can become the basis for future generations of computing devices and processors.”
The carbon transistor was created by simultaneously applying physical force and a low electrical voltage to a “crude” carbon nanotube consisting of several layers of carbon. Such an action heated the nanotube to such a temperature that the extra outer layers were removed, and the atomic structure of the remaining single-layer nanotube was rearranged so that its property called “chirality” was changed. In other words, the transformed section of the nanotube acquired the properties of a semiconductor.
Note that the theoretical basis of this achievement has been developed by the group of Professor Dmitry Golberg from NUST “MISIS”, which conducted a series of simulations and explained how changes in the atomic structure turns a nanotube into a transistor. The nanotube conversion experiment itself was conducted by the team of Dr. Dai-Ming Tang from the International Center for Materials Nanoarchitectonics in Japan.
However, the proposed method of thermo-mechanical processing of each individual carbon nanotube to turn it into a transistor is not very practical for the conditions of mass production, because modern microprocessors include tens of billions of transistors connected to one common circuit. Nevertheless, this technology is already the first practical step towards replacing silicon transistors with something else, because further reduction of the size of silicon transistors begins to face a number of technical difficulties imposed by fundamental physical limitations.
