Description
Controlling the optical response of two-dimensional semiconductors through strain has become an important strategy for improving their optoelectronic performance. Here, we report a significant enhancement of excitonic photoluminescence in monolayer MoS₂ arising from nano-needle-like oxide protrusions that develop during a photo-oxidation-assisted exfoliation process. These structures appear non-uniformly across the monolayer surface and locally distort the lattice, creating strain fields within the MoS₂ layer. Photoluminescence and Raman measurements reveal that regions containing these structures exhibit markedly stronger emission, with the photoluminescence intensity increasing by nearly twofold and accompanied by a red shift of the in-plane Raman mode consistent with strain. In addition, certain thinned monolayers and partially exfoliated bulk areas display low-energy photoluminescence features not present in pristine MoS₂. Overall, the results demonstrate that nano-needle-induced strain provides an effective route for manipulating excitonic recombination and tuning the optical properties of monolayer MoS₂.
| I am the presenting author | Yes |
|---|