Optimized plasmonic enhancement and deformation reduction in MoS₂ monolayers using Au-nanowire-embedded polymers

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Hybrid systems combining transition metal dichalcogenides (TMDs) and metal nanostructures are crucial for controlling light-matter interactions.
• Molybdenum disulfide (MoS2) monolayers are promising 2D materials for optoelectronic applications, but their light-emitting properties can be limited.

Purpose of the Study:

• To develop an effective method for integrating exfoliated MoS2 monolayers with gold nanowire (AuNW)-embedded polymer films.
• To investigate the impact of localized surface plasmon excitation in AuNWs on the optical properties of MoS2 monolayers.
• To evaluate the role of AuNWs in mitigating mechanical strain and enhancing photoluminescence (PL) in MoS2.

Main Methods:

• Integration of exfoliated MoS2 monolayers onto polydimethylsiloxane (PDMS) films embedded with AuNWs.
• Optical characterization techniques to analyze light scattering and photoluminescence.
• Numerical simulations to understand the plasmonic enhancement mechanisms.
• Assessment of mechanical deformation and strain effects on MoS2 monolayers.

Main Results:

• Localized surface plasmon excitation in AuNWs significantly enhances light scattering from MoS2.
• A five-fold increase in photoluminescence intensity of MoS2 monolayers was observed on AuNW-embedded PDMS substrates.
• The enhancement is attributed to intensified electric fields due to the dielectric contrast between PDMS and air.
• Embedding AuNWs effectively reduced mechanical deformation of MoS2, suppressing exciton dissociation.

Conclusions:

• AuNW-embedded PDMS films provide a robust platform for enhancing MoS2 photoluminescence.
• The hybrid system demonstrates significant potential for advanced TMD-based plasmonic device applications.
• This approach offers a pathway to improved light-matter interaction and device stability in 2D material systems.