Evolutionary selection growth of two-dimensional materials on polycrystalline substrates

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• High-quality, large-size single crystals of two-dimensional (2D) materials are in high demand.
• Epitaxial growth, a common method for thin film preparation, requires expensive single-crystal substrates.
• Existing methods face limitations in scalability and substrate dependency for producing large-area 2D materials.

Purpose of the Study:

• To develop a new method for synthesizing single-crystal-like monolayer graphene films on polycrystalline substrates.
• To demonstrate a scalable and cost-effective approach for producing large-area 2D materials.
• To adapt the evolutionary selection concept for 2D material synthesis.

Main Methods:

• Utilized an approach inspired by the Czochralski process and evolutionary selection.
• Employed 'self-selection' of the fastest-growing domain orientation in a 2D geometry.
• Synthesized monolayer graphene films on polycrystalline substrates.

Main Results:

• Successfully produced foot-long monolayer graphene films with single-crystal quality.
• Achieved synthesis rates of up to 2.5 cm/h.
• Demonstrated the feasibility of producing large-area 2D materials on inexpensive polycrystalline substrates.

Conclusions:

• The proposed evolutionary selection method enables the synthesis of high-quality, single-crystal-like 2D materials on polycrystalline substrates.
• The technique offers a scalable and efficient alternative to traditional epitaxial growth.
• This approach holds potential for the synthesis of other 2D materials and heterostructures.