# Biaxial strain tuning of interlayer excitons in bilayer MoS2

## TL;DR

This study demonstrates that biaxial strain significantly affects interlayer and intralayer excitonic features in bilayer MoS2, revealing strain-dependent gauge factors and the influence of van der Waals interactions.

## Contribution

It provides the first quantitative analysis of how biaxial strain tunes interlayer excitons and gauge factors in bilayer MoS2, highlighting the role of van der Waals interactions.

## Key findings

- Interlayer exciton shifts with larger gauge factor than A exciton.
- Gauge factors for A and B excitons are -41 and -45 meV/% respectively.
- Interlayer exciton gauge factor is -48 meV/%, larger due to strain-tunable van der Waals interaction.

## Abstract

We show how the excitonic features of biaxial MoS2 flakes are very sensitive to biaxial strain. We find a lower bound for the gauge factors of the A exciton and B exciton of (-41 +- 2) meV/% and (-45 +- 2) meV/% respectively, which are larger than those found for single-layer MoS2. Interestingly, the interlayer exciton feature also shifts upon biaxial strain but with a gauge factor that is systematically larger than that found for the A exciton, (-48 +- 4) meV/%. We attribute this larger gauge factor for the interlayer exciton to the strain tunable van der Waals interaction due to the Poisson effect (the interlayer distance changes upon biaxial strain).

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Source: https://tomesphere.com/paper/1908.03247