# Valley-engineering mobilities in two-dimensional materials

## TL;DR

This paper demonstrates how valley engineering via uniaxial strain can significantly enhance mobility in two-dimensional materials, exemplified by arsenene, with potential applications across similar materials.

## Contribution

It introduces a strain-based valley engineering approach to suppress intervalley scattering and improve mobility in 2D semiconductors, with detailed analysis on arsenene.

## Key findings

- Uniaxial strain lifts valley degeneracies and suppresses scattering.
- A 2% strain increases arsenene mobility by 600%.
- The approach is applicable to other 2D materials like antimonene and blue phosphorene.

## Abstract

Two-dimensional materials are emerging as a promising platform for ultrathin channels in field-effect transistors. To this aim, novel high-mobility semiconductors need to be found or engineered. While extrinsic mechanisms can in general be minimized by improving fabrication processes, the suppression of intrinsic scattering (driven e.g. by electron-phonon interactions) requires to modify the electronic or vibrational properties of the material. Since intervalley scattering critically affects mobilities, a powerful approach to enhance transport performance relies on engineering the valley structure. We show here the power of this strategy using uniaxial strain to lift degeneracies and suppress scattering into entire valleys, dramatically improving performance. This is shown in detail for arsenene, where a 2% strain stops scattering into 4 of the 6 valleys, and leads to a 600% increase in mobility. The mechanism is general and can be applied to many other materials, including in particular the isostructural antimonene and blue phosphorene.