On-Chip Synthesis of Quasi-2D Semimetals from Multi-Layer Chalcogenides

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Reducing material dimensions to quasi-two dimensions (quasi-2D) is crucial for exploring quantum phenomena and developing advanced electronics.
• Synthesizing high-quality, ultrathin, quasi-2D materials on arbitrary substrates remains a significant challenge.

Purpose of the Study:

• To demonstrate a simple, reproducible on-chip method for synthesizing non-layered, nanometer-thick, quasi-2D semimetals.
• To explore the generalizability of this synthesis approach for various 2D layered chalcogenides.

Main Methods:

• Utilizing thin semiconducting indium selenide (InSe) flakes (<20 nm) with deposited nickel.
• Employing low-temperature annealing to induce a controlled transformation via nickel reaction and lateral diffusion.
• Characterizing the resulting semimetal using atomic resolution microscopy.

Main Results:

• Successfully synthesized a non-layered, crystalline semimetal, identified as Ni3In2Se2, featuring a Kagome-lattice structure.
• Demonstrated the generalizability of the method by transforming other 2D layered chalcogenides (SnS, SnSe) into non-layered semimetals using Ni and Co.

Conclusions:

• The developed on-chip approach provides a viable route for templated synthesis of quasi-2D semimetals.
• This method opens avenues for engineering novel electronic devices based on newly synthesized non-layered materials.