Work

Self-Assembled Oxide Nanoneedle-Induced Strain for Tunable Excitonic Emission in Monolayer MoS2

Year: 2026

Type: article

Abstract: Strain engineering has emerged as a powerful approach for tailoring the optical response of two-dimensional semiconductors. In this work, we show that monolayer MoS2 exhibits tunable excitonic emission, when nanoneedle-like oxide protrusions form across the monolayer surface during a photo-oxidation-assisted exfoliation process. These protrusions locally deform the lattice, generating spatially varying strain fields within the MoS2 layer. Photoluminescence and Raman measurements reveal a clear correlation between strained regions, exciton peak shifts, and enhanced emission, with the photoluminescence intensity increasing by approximately 3-fold, accompanied by a red shift of the in-plane (E2g1) vibrational mode, indicative of strain. Furthermore, selected monolayers and unexfoliated regions exhibit additional emergent near-infrared photoluminescence features absent in pristine MoS2. Unlike conventional strain-engineering approaches requiring external mechanical deformation, specialized substrate prepatterning, or complex heterostructures, this simple one-step process generates intrinsic nanoneedle-induced strain, providing an effective route for tailoring excitonic recombination and extending the optical response of monolayer TMDCs.

Source: ACS Omega

DOI: 10.1021/acsomega.6c04805

Authors: Rashed H. Lone, Shreya Gaonkar, Deepak Sharma, Shruti Nirantar, E. S. Kannan

Institutions: Birla Institute of Technology and Science, Pilani - Goa Campus, Birla Institute of Technology and Science, Pilani, RMIT University

Language: English

Topic: 2D Materials and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: Australian National Fabrication Facility, RMIT University