Scientists have grown a flawless 2D-crystall on silicon
In the figure: the forming of a two-dimensional monoclinic m-GaTe on a silicon wafer
MIET scientists together with their colleagues from Germany and Italy proposed a new technology to produce gallium telluride, an important substance for modern electronics. The result of their research was published in npj 2D Materials and Applications, a journal that belongs to Springer Nature.
The future of modern electronics is directly related to new materials and their integration into chip manufacturing technologies. According to experts, the so-called two-dimensional (2D) materials with unique properties have recently attracted great interest.
This class of materials has a layered structure. The atoms within a single layer are bound by rigid shared electron bonds; the layers are interconnected by weak intermolecular Van der Waals bonds. Experts note that controlled creation of such structures on standard semiconductor wafers poses many problems. The most important of them is defects at the junction of the formed material and the wafer caused by structural inconsistencies between the crystal lattices. Such defects greatly reduce the efficiency of 2D materials and negatively affect their structure.
A team of MIET specialists and their foreign colleagues managed to solve this problem by proposing a new method of growing 2D gallium telluride crystals on a silicon wafer. According to the scientists, the new method makes it possible to integrate this compound with in-demand nonlinear optical properties into the already existing technology of chip production.
“Gallium telluride has two structural forms: hexagonal and monoclinic, and it is the latter that has the necessary properties. We formed it on the surface of monocrystalline silicon in two stages: first, by molecular beam epitaxy the hexagonal phase is grown on the wafer, and then energy is introduced by burning, provoking its transformation into a monoclinic phase,” said Alexander Prikhodko, senior researcher of the electron microscopy laboratory and associate professor at the Institute of Physics and Applied Mathematics.
Gallium telluride obtained by this method has a stable optically active structure. The use of such material in electronics will make it possible to develop new photodetectors, elements for solar batteries or new generation displays.
The research has also clarified the fundamental mechanisms underlying the process of growing 2D crystals on semiconductors. The data obtained will be useful in further development of this promising technology.
Experts from Technical University of Munich, University of Tor Vergata, University of Milan-Bicocca, and Institute of Microelectronics and Microsystems also participated in the research.
The research team intends to continue both the development of other two-dimensional materials on a silicon substrate and the fundamental research in this field.