# Metallic edge states in zig-zag vertically-oriented MoS2 nanowalls

## TL;DR

This study demonstrates that zig-zag edges in MoS2 nanowalls exhibit metallic properties, achieved through precise edge patterning, opening new avenues for designing layered material-based electronic and optoelectronic devices.

## Contribution

It introduces a top-down focus ion beam method to selectively pattern edge types in MoS2 nanostructures, revealing their distinct electronic behaviors.

## Key findings

- Zig-zag edges show metallic electronic signatures.
- Edge type control is confirmed by high-resolution TEM.
- Potential for tailored nanostructure design in electronics.

## Abstract

The remarkable properties of layered materials such as MoS2 strongly depend on their dimensionality. Beyond manipulating their dimensions, it has been predicted that the electronic properties of MoS2 can also be tailored by carefully selecting the type of edge sites exposed. However, achieving full control over the type of exposed edge sites while simultaneously modifying the dimensionality of the nanostructures is highly challenging. Here we adopt a topdown approach based on focus ion beam in order to selectively pattern the exposed edge sites. This strategy allows us to select either the armchair (AC) or the zig-zag (ZZ) edges in the MoS2 nanostructures, as confirmed by high-resolution transmission electron microscopy measurements. The edge-type dependence of the local electronic properties in these MoS2 nanostructures is studied by means of electron energy-loss spectroscopy measurements. This way, we demonstrate that the ZZ-MoS2 nanostructures exhibit clear fingerprints of their predicted metallic character. Our results pave the way towards novel approaches for the design and fabrication of more complex nanostructures based on MoS2 and related layered materials for applications in fields such as electronics, optoelectronics, photovoltaics, and photocatalysts.