Defect-Free Nanowelding of Bilayer SnSe Nanoplates

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Nanowelding offers a bottom-up approach for fabricating nanostructures with precision exceeding lithographic methods.
• Controlling crystal orientation and interface quality is crucial for advanced nanodevices.
• Van der Waals (vdW) heterostructures offer unique properties due to their layered nature and tunable interfaces.

Purpose of the Study:

• To introduce a new nanowelding technique for precise control over crystal orientation and interface formation.
• To leverage anisotropic lubricity at vdW interfaces for controlled manipulation and assembly of nanostructures.
• To demonstrate the potential for constructing complex quantum devices using this method.

Main Methods:

• Utilized anisotropic lubricity at the vdW interface between tin selenide (SnSe) nanoplates (monolayer and bilayer) and a graphene substrate.
• Employed scanning tunneling microscopy (STM) to manipulate SnSe nanoplates (30-100 nm) at room temperature.
• Applied in situ annealing to achieve defect-free welding of contacted nanoplates.

Main Results:

• Achieved precise control of crystal orientation by exploiting the commensuration mismatch between SnSe and graphene along zigzag directions, enabling 1D rail-like movement.
• Successfully welded SnSe nanoplates with high precision and without atomic defects at the interface.
• Demonstrated a technique applicable to various vdW interfaces exhibiting anisotropic lubricity.

Conclusions:

• The reported nanowelding technique offers unprecedented control over nanostructure assembly via anisotropic lubricity.
• This method is highly promising for fabricating complex quantum devices, including transistors, quantum interference devices, and qubits.
• The approach is generalizable to other vdW systems, opening new avenues in nanoscale engineering.