In physics, Professor Kwan-pyo Kim's research team actually synthesized group IV-VI monochalcogenide(group IV-VI monochalcogenide)of a new structure predicted only by theory through experiments and reported it to academia.

Group 4-6 chalcogen compound groups were previously expected to have various structures of compounds, but actual discoveries of new compound structures were not uncommon. The researchers were the first to implement compounds of hexagonal crystal structure in groups 4-6 single chalcogen groups, opening new avenues for structural control and applied research of chalcogen materials.

Group 4-6 single chalcogen compounds have a layered structure in which the atomic layers are stacked, and it has been known that the existing chalcogen compounds have a wrinkled-shaped layer. These layered structures have recently been in the limelight due to their high applicability to semiconductor and phase-changing memory devices. Black phosphorus(black phosphorus)having a similar wrinkled layered structure has been noted as a next-generation semiconductor material, in the case of chalcogen compounds are used in the phase change memory device using the fact that it can have a variety of structures.

Professor Kwan-Pyo Kim's team succeeded in synthesizing the third polymorph of germanium selenide(GeSe), a group 4-6 compound, for the first time by chemical Vapor deposition(Chemical Vapor Deposition)method. The latest electron microscope analysis method has successfully achieved a new material structure analysis, and it has been revealed for the first time that it has an atomic four-layer thick layer structure(quadruple-layer)in addition to a hexagonal structure that was not seen in existing group 4-6 compounds. It was also confirmed that the newly synthesized germanium selenide compound has very high electrical conductivity.

“Our first experimental implementation of hexagonal crystal synthesis of group 4-6 chalcogen compounds will lay the foundation for a variety of basic research on strong current and thermoelectric applications, along with the discovery of new types of chalcogen polymorphs,”the researchers explained.

This research was published on May 10(local time) in Nano Letters(IF=11.238), a global journal in the field of nano, and was supported by the Korea Research Foundation's leading Research Center support project(Van Der Waals Materials Research Center) and the Emerging research support project.