Programmable nanowrinkle-induced room-temperature exciton localization in monolayer WSe₂

Area of Science:

• Materials Science
• Quantum Physics
• Nanotechnology

Background:

• Localized states in 2D transition metal dichalcogenides (TMDCs) are crucial for quantum information science but their microscopic origins remain unclear.
• Nanowrinkles have shown potential for generating strain-localized room-temperature emitters in TMDCs.

Purpose of the Study:

• To demonstrate a method for intentionally inducing and controlling wrinkles in 2D TMDCs using patterned stressors.
• To investigate the correlation between wrinkle properties, strain, and localized exciton emission.
• To confirm the formation of quantum emitters at cryogenic and room temperatures.

Main Methods:

• Fabrication of patterned arrays of stressors to induce wrinkles.
• Nano-photoluminescence (nano-PL) imaging to map exciton emission.
• Detailed strain modeling based on measured wrinkle topography.
• Hyperspectral imaging at room temperature and emission analysis at cryogenic temperatures.

Main Results:

• Long-range wrinkle direction and position were controllable via patterned array design.
• A correlation was established between wrinkle properties (especially shear strain) and localized exciton emission.
• Quantum emitters were confirmed at cryogenic temperatures, and confined low-energy emission states (<10 nm) were observed at room temperature.

Conclusions:

• Intentional wrinkle induction provides a controllable route to generate strain-localized quantum emitters in 2D TMDCs.
• This approach shows significant potential for realizing room-temperature quantum emission in these materials.
• Understanding the role of shear strain and fine wrinkle heterogeneity is key for optimizing emitter properties.