# Measurement of local optomechanical properties of a direct bandgap 2D semiconductor

## TL;DR

This paper presents a novel method for local measurement of strain effects on excitonic photoluminescence in monolayer TMDs, enabling detailed optomechanical characterization at the nanoscale.

## Contribution

It introduces a reversible AFM-based stress technique combined with spatio-spectral mapping to analyze local optomechanical properties of 2D semiconductors.

## Key findings

- Strain linearly affects exciton energy and photoluminescence intensity.
- Method accurately reproduces experimental data with optical resolution considerations.
- Approach enables nanoscale optomechanical studies of 2D semiconductors.

## Abstract

Strain engineering is a powerful tool for tuning physical properties of 2D materials, including monolayer transition metal dichalcogenides (TMD) -- direct bandgap semiconductors with strong excitonic response. Here, we demonstrate an approach for local characterization of strain-induced modification of excitonic photoluminescence in TMD-based materials. We reversibly stress a monolayer of MoSe$_2$ with an AFM tip and perform spatio-spectral mapping of the excitonic photoluminescence in the vicinity of the indentation point. To fully reproduce the experimental data, we introduce the linear dependence of the exciton energy and corresponding photoluminescence intensity on the induced strain. Careful account for the optical resolution allows extracting these quantities with good agreement with the previous measurements, which involved macroscopic sample deformation. Our approach is a powerful tool for the study of local optomechanical properties of 2D direct bandgap semiconductors with strong excitonic response.