Epitaxial Growth and Electronic Properties of Graphene on Silicon Carbide

Epitaxial graphene on silicon carbide (SiC) is produced by thermal decomposition of the SiC surface at elevated temperatures, during which silicon atoms sublimate and remaining carbon atoms reorganise into sp2-bonded graphene layers. The initial carbon layer, commonly known as the buffer layer, retains partial sp3 character and remains electronically coupled to the substrate. Subsequent layers form true graphene with Dirac-like band dispersion. Control of growth parameters—temperature, ambient pressure (inert gas or vacuum) and substrate face orientation—enables large-area, uniform films with tunable thickness. Intercalation of species such as hydrogen or metals beneath the buffer layer decouples graphene from SiC, creating quasi-free-standing graphene with enhanced carrier mobility and adjustable doping. Characterisation techniques including low-energy electron diffraction and microscopy (LEED/LEEM), angle-resolved photoelectron spectroscopy (ARPES), Raman spectroscopy, atomic force microscopy (AFM) and Hall measurements provide insight into morphology, stacking order, electronic band structure and transport properties. The combination of wafer-scale uniformity, high carrier mobility and compatibility with existing semiconductor technologies renders epitaxial graphene on SiC a promising platform for quantum resistance standards, high-frequency transistors, sensors and emerging two-dimensional heterostructure devices.

Research from Nature Portfolio

Recent studies have shown that hydrogen intercalation beneath epitaxial graphene on 4H-SiC(0001) saturates silicon dangling bonds at the interface, converting the buffer layer into a quasi-free-standing monolayer. This process increases carrier mobility from around 3 000 cm2 V−1 s−1 to over 11 000 cm2 V−1 s−1 at cryogenic temperatures and reduces electron concentration to below 1×1012 cm−2. In parallel, exploration of as-grown and ex-situ intercalated graphene via Kelvin probe force microscopy and Raman mapping has revealed a carrier type inversion from n- to p-type, accompanied by a threefold enhancement of hole mobility and work function shifts. These advances underpin applications in quantum metrology and high-speed electronics by delivering uniform graphene with controllable carrier polarity and minimal substrate interference.

Epitaxial Growth and Electronic Properties of Graphene on Silicon Carbide publication trend

The graph below shows the total number of articles in epitaxial growth and electronic properties of graphene on silicon carbide across all publications each year (not limited to Nature Index journals).

Technical terms

Epitaxial growth: Formation of graphene layers on SiC by high-temperature decomposition and carbon reorganisation aligned to the substrate lattice.

Intercalation: Insertion of atoms or molecules between graphene and the SiC substrate to alter electronic coupling and doping.

Quasi-free-standing graphene: Graphene layers electronically decoupled from SiC after intercalation, restoring intrinsic sp2 bonding and high mobility.

Angle-resolved photoelectron spectroscopy (ARPES): Technique that maps the electronic band structure by measuring the energy and emission angles of photo-emitted electrons.

Van Hove singularity: A point in the electronic density of states where a saddle point in the band structure leads to a divergence, enhancing interaction effects.

References

1. Epitaxial Graphene on SiC: A Review of Growth and Characterization. Crystals (2016).
2. High Electron Mobility in Epitaxial Graphene on 4H-SiC(0001) via post-growth annealing under hydrogen. Scientific Reports (2014).
3. Carrier type inversion in quasi-free standing graphene: studies of local electronic and structural properties. Scientific Reports (2015).
4. Large‐Area Lead Monolayers under Cover: Intercalation, Doping, and Phase Transformation. Small Structures (2024).
5. Overdoping Graphene beyond the van Hove Singularity. Physical Review Letters (2020).