Graphene

Physics / mechanism

Single-atom-thick carbon lattice (sp² hybridised), hexagonal arrangement giving exceptional in-plane properties: intrinsic carrier mobility ~200,000 cm²/V·s (theoretical; practical CVD graphene ~10,000–50,000 cm²/V·s on SiO₂), thermal conductivity ~5,000 W/m·K, tensile strength ~130 GPa, optical transmittance ~97.7% per layer. Zero bandgap in pristine form limits digital switching; engineering a gap (bilayer twist, chemical functionalisation, nanoribbons) sacrifices mobility. CVD on Cu foil is the dominant synthesis route for large-area films; epitaxial growth on SiC reaches higher quality but at wafer cost. Transferred graphene onto target substrates remains a yield and contamination bottleneck limiting device integration.

Competitive landscape

Key substitutes by application: MoS₂ and other TMDs offer a native bandgap (~1.8 eV monolayer MoS₂) where switching is needed. hBN serves as a superior dielectric substrate, often used with graphene rather than competing directly. Silicon photonics covers most electro-optic modulator applications at lower integration risk. ITO remains the incumbent transparent conductor despite inferior RF performance. For RF/THz transistors, III-V (GaN, InP HEMTs) hold the high-performance benchmark. Graphene wins on flexibility, broadband optical absorption, and RF linearity where substrate integration is solved.

Companies using

Connected ideas

Sources

Frontier (open questions)

• To be added.