Simultaneous assembly of van der Waals heterostructures into multiple nanodevices

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Van der Waals heterostructures (vdWH) are novel materials composed of stacked 2D layers with tunable properties.
• Current fabrication methods for vdWHs, like mechanical stamping, are slow and not scalable.
• Naturally occurring vdWHs, such as franckeite, offer an alternative but require exfoliation.

Purpose of the Study:

• To develop a scalable and fast method for fabricating vdWH nanodevices.
• To demonstrate the preservation of vdWH properties after fabrication.
• To enable large-scale studies and applications of vdWHs.

Main Methods:

• Liquid phase exfoliation of 2D materials to obtain nanoflakes.
• Dielectrophoretic assembly for simultaneous transport and positioning of multiple nanoflakes into submicrometer structures.
• Fabrication of field-effect transistors using the assembled vdWHs.

Main Results:

• A scalable and fast fabrication method for vdWH nanodevices was successfully developed.
• Dielectrophoretic assembly preserved the complex vdWH structure.
• The fabricated vdWH field-effect transistors exhibited properties equivalent to those made by mechanical exfoliation and stamping.

Conclusions:

• The combination of liquid phase exfoliation and dielectrophoretic assembly offers a scalable route for vdWH nanodevice fabrication.
• This method is suitable for both fundamental research on vdWHs and applications requiring large-scale production.
• The reported technique overcomes limitations of traditional manual fabrication methods.