Ultrahigh-mobility semiconducting epitaxial graphene on silicon carbide

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanoelectronics

Background:

• Graphene lacks an intrinsic bandgap, hindering its use in nanoelectronics.
• Previous attempts to engineer graphene's bandgap have been unsuccessful.
• The first graphitic layer on SiC is an insulating epigraphene buffer layer.

Purpose of the Study:

• To develop a viable semiconducting graphene material for nanoelectronics.
• To overcome the limitations of previous semiconducting graphene approaches.
• To create a well-ordered epigraphene layer with high charge carrier mobility.

Main Methods:

• Utilized quasi-equilibrium annealing on single-crystal silicon carbide substrates.
• Graphene multilayers were formed by silicon evaporation from SiC.
• Characterized the epigraphene buffer layer using spectroscopic measurements.

Main Results:

• Achieved semiconducting epigraphene (SEG) with a 0.6 eV band gap.
• Demonstrated room temperature mobilities exceeding 5,000 cm² V⁻¹ s⁻¹.
• SEG exhibits chemical, mechanical, and thermal robustness, and can be patterned.

Conclusions:

• Semiconducting epigraphene is a promising material for nanoelectronics.
• The developed method produces high-quality, well-ordered SEG suitable for fabrication.
• SEG's properties are superior to silicon and other 2D semiconductors for electronic applications.