Exploring new low-dimensional carbon nanomaterials and their novel properties has always been one of the forefront scientific issues in the field of science and technology. The two-dimensional graphene lattice structure is considered to be the parent material of many other carbon nanostructures. For example, the graphene structure is curled in a certain direction to form a one-dimensional carbon nanotube, and the five-membered ring and the seven-membered ring graphene structure are bent into a spherical structure to form a fullerene. The application of graphene in future nanotechnology devices requires the construction of new functionalized graphene nanostructures with three-dimensional morphology and precise complexity. The precise construction and regulation of graphene-based low-dimensional carbon nanostructures at the single-atom level still presents significant challenges.
"Origami" is an art that folds paper out of various shapes and patterns. Through subtle techniques, the artists transform simple and monotonous two-dimensional paper into colorful three-dimensional structures. Inspired by this art, folding manipulation is often used in many frontiers of science and technology to construct structures, devices and even machines with different shapes and functions. For example, the field of biology can fold DNA single-chain into complex two. Dimensional shape. At the macro scale, inspired by origami, scientists have been able to construct graphene functional devices and even machine models. Theoretical predictions show that at the atomic scale, nanostructures with novel electronic properties can be constructed by bending and folding graphene. However, the electronic properties of the graphene curved structure are susceptible to localized vacancies, atomization, boundary and other defect structures. Accurately folding graphene on a single atomic scale, especially folding graphene in a particular direction according to specific needs, is extremely challenging.
Recently, Chen Hui, a member of the Chinese Academy of Sciences and a researcher at the Institute of Physics of the Chinese Academy of Sciences, has achieved atomic-level precise controllable folding of graphene nanostructures for the first time, and constructed a new type of quasi-three-dimensional graphene nanostructures. The structure consists of a two-dimensional rotating stack of two-layer graphene nanostructures and a one-dimensional carbon-like carbon nanotube structure. They use scanning probe manipulation technology to achieve: (1) atomic-level precision folding and unfolding of graphene nanostructures; (2) repeated folding of the same graphene structure in any direction; (3) accurate stacking angle Rotating stacked double-layer graphene nanostructures; (4) construction of quasi-one-dimensional carbon nanotube nanostructures; (5) controllable folding of bicrystal graphene nanostructures and construction of heterojunctions. They applied the scanning tunneling spectrum and the first-principles calculation to determine the exact atomic configuration and local electronic structure of the folded graphene nanostructures. It was found that the quasi-one-dimensional nanotube heterojunction obtained by graphene "nano-origination" has Different energy bands are arranged.
For the first time in the world, this work has achieved atomic precision control, on-demand graphene folding, which is currently the world's smallest size graphene folding. Based on this atomic-level precision "origami", it is also possible to fold other new two-dimensional atomic crystal materials and complex laminated structures to prepare functional nanostructures and their quantum devices, and to study their novel physical phenomena. For example, to explore the superconductivity, topological properties and magnetic properties of the two-dimensional two-dimensional atomic crystal material of the magic angle rotating stack, and to study the transport properties and applications of the one-dimensional heterojunction. This research work has important scientific and technical significance for constructing quantum materials and quantum devices (machines).
Chen Hui, Zhang Xianli and Zhang Yuyang are the co-first authors of the paper, and Du Shizhen and Gao Hongjun are co-authors. Professor Ouyang Min from the University of Maryland and S. T. Pantelides from Vanderbilt University participated in the discussion and cooperation. The research was titled Atomically precise, custom-design origami graphene nanostructures on September 6th in the journal Science .