Physics / mechanism
Atomically thin crystalline solids — one to few atomic layers — with properties discontinuous from their bulk counterparts. Graphene (zero-bandgap semimetal, carrier mobility >200,000 cm²/V·s on hBN), transition metal dichalcogenides (TMDs: MoS₂, WSe₂, bandgaps 1–2 eV, direct-gap in monolayer form), hexagonal boron nitride (hBN, wide-gap insulator, flat-band substrate), and MXenes (metallic/semiconducting carbides). Key parameters: layer count, defect density, substrate coupling, contact resistance. Wafer-scale CVD graphene now routine; TMD monolayers transferred to 200 mm wafers in research fabs. Contact resistance and dielectric integration remain the hard problems blocking device-grade yield.
Competitive landscape
Competing and adjacent approaches for the same device targets — sub-3 nm logic, RF transistors, photodetectors, neuromorphic elements:
| Approach | Mobility advantage | CMOS integration risk | Maturity |
|---|---|---|---|
| 2D TMDs (MoS₂, WSe₂) | High (intrinsic), degraded (contacts) | Moderate — low-T deposition | TRL 4–6 |
| III-V heterostructures (InGaAs) | Very high | High — lattice mismatch, cost | TRL 7–9 |
| Si/SiGe nanosheets | Moderate | Low — fab-native | TRL 8–9 (GAA) |
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.