Russian and American scientists created the first one-dimensional semiconductor material in the world. It was received from synthetic material Ta-Pd(Pt)-Se using micromechanical cleavage method, which was used in the process of graphene discovery. Using the new semiconductor in microelectronics will reduce electronic circuits to nano-circuits in size and increase the speed of devices.
The theoretical part of the study was performed by the scientists of NRTU MISIS under the guidance of the doctor of physical and mathematical sciences, Pavel Sorokin. The experimental part of the work was developed by American colleagues from Tulane University headed by the Professor Jan Vey.
They have tried to develop the dimensional semiconductor since 1990s. There were attempts to cut the graphene, but the sensitivity of the conducting properties didnt allow using the resulting material in electronics. Then, they were trying to get strips from two-dimensional semiconductors, but since they were composed of chemically bonded three-atom layers, the attempt to cut them into strips the right way failed.
A team of scientists from MISIS and Tulane University approached the problem from a fundamentally different side. It was decided to look for a crystal consisting of loosely coupled one-dimensional nanostructures to apply the micromechanical cleavage method.
Ta2Pt3Se8 (thallium-platinum-selenium) and Ta2Pd3Se8 (thallium-palladium-selenium) synthesized more than 30 years ago (but it is still not widespread) was the material they used.
The direct method to get strips from quasi-dimensional graphene and dichalcogenides of transition metals (MoS2, WS2, and so on) by cutting them (e-beam lithography, chemical etching, etc.) doesnt allow producing the extended objects with acceptable quality. In our work we used a fundamentally different approach, that is, dividing the crystal that was already composed of quasi-one-dimensional strips into components - Sorokin explains. We started working almost immediately, as soon as our colleagues began to conduct systematic experiments.
Preliminary calculations showed that the crystal Ta2Pd3Se8 has a rather weak connection between the strips, afterwards we concluded that it was possible to receive ultrathin nanowires consisting of only a few strips, or simply separate strips ribbons.
It gave them encouragement, then we started working in parallel - we analyzed the properties of the material, and they performed its synthesis. In general, our work took about a year.
According to the scientist the new material will be used primarily in integrated circuits. Colleagues from the United States on the basis of wires have already produced the transistor, which showed good performance. The work isnt over yet, in the experiment we will have to improve the quality of the synthesized nanostructures, which will enable us to declare that a new material for electronics was developed, - Sorokin emphasizes. - But the most important thing is that the first step in this direction has already been made.
Meanwhile, on the basis of new materials TSU is going to establish hydrogen production technology of renewable batteries (fuel cells), which are more environmentally friendly and analogues can be used in any way in the places, where energy is needed, for example, in Africa or in the Arctic.
- Pure hydrogen and oxygen, which can be obtained from the air, is needed for such batteries. They are already being used, but there is one problem: where can we get the hydrogen? It is difficult and expensive to transport. And if you use nanomaterials produced by LLC Advanced Powder Technology and TSU, which react with water, it is possible to produce hydrogen directly at the site - the professor of the Institute of Technology of New Jersey, a visiting professor at TSU, Edward Dreizin, said.
He explained that it was about nano-dispersed powders, that scientists from high-energy laboratories and special materials of TSU learned to produce using electric explosion technology. The nanoparticles developed at TSU, enable to set the required properties, and the scope of application of nanomaterials obtained is very wide: from aerospace industry to medicine.
According to Professor Dreizen, another point of application of new materials may be alternative sources of energy. Unlike conventional batteries, hydrogen batteries dont harm the environment.
- These hydrogen batteries can be used in any remote, inaccessible places where energy is needed, but there is no way to hold power line. The water in these areas is much easier to find, and therefore, our technology will be in demand, - Edward Dreizin explained.
He noticed that it was a full development of material application technology - from optimizing them to preparing them for implementation. The scientists from the USA, Italy and Jamaica are supposed to join the work. Nowadays the team is looking for funding for the project.