Nanomolding nanowires for high throughput screening of topological materials

Topological materials possess unique symmetry-protected electronic states, which can lead to interesting properties and resistance to external perturbations like changes in pressure or temperature. In topological insulators, for example, the bulk of the material is insulating, but the surface is conductive.

These materials could be applied in quantum computing, catalysis, and various sensors, but they have yet to be used widely because they are difficult or time-consuming to fabricate.

Kiani and Cha described how nanomolding can be used to fabricate topological materials. They provided several candidate materials and outlined the steps to create nanowires.

“We estimated in the paper that it takes one graduate student one year to fabricate a single composition nanowire with traditional nanofabrication methods,” said author Mehrdad Kiani. “These approaches are not practical for high throughput screening of topological or transport properties.”

Nanomolding could become a much faster and more reliable alternative. The method is very similar to traditional molding and requires a similar setup: bulk feedstock, a honeycomb-like mold, and a hot press. After placing the mold and bulk feedstock in contact, the combination is pressed together, and the mold is etched away to leave nanowires.

The technique can deal with many different topological materials, and changing the pores of the mold can easily control the output size. The nanowires are single crystalline with the same orientation and have minimal defects.

By providing a straightforward introduction to nanomolding, the authors hope others will be encouraged to implement it. The team plans to study the technique for more complicated nanostructures, which would require alternative mold structures and materials, and explore a wider variety of crystal classes and chemical compositions.

Source: “Nanomolding of topological nanowires,” by Mehrdad T. Kiani and Judy J. Cha, APL Materials (2022). The article can be accessed at https://doi.org/10.1063/5.0096400 .

This paper is part of the Materials Challenges and Synthesis Science of Emerging Quantum Materials Collection, learn more here .