MOSCOW, May 22.Scientists from NRU MIET, together with colleagues from Italy and Germany, have proposed a new technology for producing two-dimensional gallium telluride, an important material for advanced electronics. The results of their research are published in Springer Nature's journal npj 2D Materials and Applications.
The future of modern electronics is directly related to the creation of new materials and their integration into chip manufacturing technologies. Now, according to experts, the so-called two-dimensional (2D) materials with unique properties are of great interest.
Materials of this class have a layered structure, the scientists explained. Within a single layer, the atoms are linked by rigid covalent bonds, and the layers are interconnected by weak intermolecular van der Waals bonds.
Experts note that the controlled creation of such structures on standard semiconductor substrates is associated with many problems. The most important of them are defects at the junction of the formed material and the substrate, caused by structural mismatches between the crystal lattices. Such defects greatly reduce the efficiency of 2D materials and negatively affect their structure.
The team of specialists from the National Research University «MIET» and their foreign colleagues managed to solve this problem by proposing a new method for growing 2D gallium telluride crystals on a silicon substrate. According to the scientists, the development makes it possible to integrate this compound with sought-after nonlinear optical properties into an existing chip manufacturing technology.
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"Gallium telluride has two structural forms — hexagonal and monoclinic, it is the latter that has the necessary properties. We carried out its formation on the surface of single-crystal silicon in two stages: first, a hexagonal phase is grown on the substrate by molecular-beam epitaxy, then, due to firing, energy is introduced that provokes its transformation into a monoclinic phase,” said senior researcher at the Laboratory of Electron Microscopy and Associate Professor of the Institute Physics and Applied Mathematics NRU "MIET" Alexander Prikhodko.
Thus obtained gallium telluride has a stable optically active structure. The use of such a material in electronics will make it possible to develop new photodetectors, elements for solar energy or for displays of a new generation.
«Structural studies have shown that a layer of monoclinic gallium telluride on silicon has an almost perfect atomic structure. The interface between the material and the substrate is sharp, there are no mismatch dislocations that cause a decrease in properties,» Prikhodko noted.
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In addition, the scientists emphasized that the research allowed to clarify the fundamental mechanisms underlying the process of growing 2D structures on semiconductors. The obtained data will be useful in the further development of this promising technology.
Specialists from the Technical University of Munich, the University of Rome Tor Vergata, the University of Milan Bicocca and the Institute of Microelectronics and Microsystems (Italy) participated in the work. Structural studies of new two-dimensional materials were carried out at the laboratory of electron microscopy of the National Research University «MIET» as part of the development strategy of the university as a participant in the program «Priority-2030» of the Ministry of Education and Science.
In the future, the research team intends to continue both the development of other two-dimensional materials on a silicon substrate, and fundamental research in this area. html» data->