Nanoimprint strain-engineering of 2D semiconductors

TL;DR

This paper introduces a scalable nanoimprint technique to create controlled inhomogeneous strain profiles in 2D semiconductors, enabling tuning of their optical properties for potential optoelectronic applications.

Contribution

The study presents a novel nanoimprint process for applying controlled inhomogeneous strain to 2D materials, verified by optical imaging, with scalability for commercial use.

Findings

Successfully created inhomogeneous strain profiles in WS2 monolayers

Verified strain profiles using hyperspectral optical imaging

Technique is scalable and adaptable to commercial nanoimprint machines

Abstract

Mechanical strain is a powerful tool to tune the optical and optoelectronic properties of atomically thin semiconductors. Inhomogeneous strain plays an important role in exciton funneling and the activation of single-photon emitters in 2D materials. Here, we create an inhomogeneous strain profile in a 2D semiconductor on a micrometer scale by a nanoimprint process. We present a nanoimprint setup, where a mold is used to apply pressure in a controlled way to a WS2 monolayer on a heated polymer layer. After printing, the strain created in the 2D semiconductor is verified by hyperspectral optical imaging. The developed nanoimprint technique is scalable and could be transferred to commercial nanoimprint machines.