Researchers at Tokyo Metropolitan University have developed a technique to scale self-assembled nanowires – and fine-tune their arrangement – using chemical vapor deposition (CVD).
To keep miniaturizing electronics and putting more computing power in the same room, it is necessary to make smaller and smaller wiring and components.
For example, a hypothetical atomic thickness wire would be the ultimate goal. This could lead to new categories of electronic and energy devices, as the electrons traveling through them behave more as if they were moving through a one-dimensional world than a three-dimensional world.
Scientists are already able to convert materials such as carbon nanotubes and transition metal chalcogenides (TMCs), mixtures of transition metals and group 16 elements that can self-assemble into atomic-scale nanowires. These have three-atom diameter (with chalcogen atoms occupying three corners of a triangular frame and metal atoms in the center of each side) and van der Waals surfaces, and have been reported to have one-dimensional metallic nature.
Although TMCs were discovered 40 years ago, creating them to scale and with usable lengths is still a challenge and the mass production of nanowires has remained unattainable so far.
Now a team from Tokyo Metropolitan University has developed a method for making long wires from transition metal telluride nanowires on an unprecedented scale.
Using CVN, they can assemble these nanowires in different configurations, depending on the substrate they use as a template. By adjusting the structure of the substrate, the researchers were able to create one-centimeter wafers covered with arrangements, including atomically thin plate-like monolayers, bilayers, and random networks of bundles of wires, all with different uses.
The structure of the nanowires themselves was highly crystalline and ordered, and their properties (including excellent conductivity and one-dimensional behavior) were consistent with those predicted by the theory.
The production of large quantities of long crystalline nanowires is valuable for further research on these structures, which has been limited so far due to the scarcity of TMC nanowire samples. It also marks an important step towards real-world nanowire applications.
“The ability to achieve large-scale synthesis and manipulate the growth direction of nanowires is important, as it provides a possible way for scalable, direct orientation patterns of TMC nanowires via surface engineering,” the researchers wrote in their Nano Letters paper. “The current findings provide a new platform for new studies and applications of [one-dimensional] nanowire systems, which contribute not only to new discoveries in basic low-dimensional physics, but also to the design of future applications in electronics and energy storage / conversion equipment. “
Header image does not depict nanowire arrays created in this study.
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