Two-dimensional semiconductors are attractive for electronics because an active layer only a few atoms thick could help engineers build denser devices and stack functional transistor layers vertically. One important obstacle, however, has been the shortage of scalable, high-performance p-type 2D semiconductors. A new study published in Nature on 30 September 2026 reports a notable step toward closing that gap: wafer-scale monolayer boron carbon nitride (BCN) that operates as a p-type semiconductor.
What changed?
The researchers engineered the chemistry used to grow BCN rather than relying on mechanically isolated flakes. Their approach controls the reaction pathways of two precursor molecules so that boron, carbon and nitrogen are delivered more uniformly during growth. Carbon atoms and carbon dimers are incorporated mainly at nitrogen sites in a continuously crystallized boron-nitride lattice, changing its electronic structure while retaining an atomically thin sheet.
The resulting BCN has a reported bandgap of 1.90 eV. Arrays of p-channel field-effect transistors showed room-temperature field-effect hole mobility of about 100 cm² V⁻¹ s⁻¹, on-current above 0.9 mA μm⁻¹ and an on/off current ratio of 10⁸. The University of Tokyo reports that the material was produced at two-inch wafer scale and that 224 transistors made from three growth batches were evaluated for device uniformity.
Why it matters
Modern complementary logic depends on both n-type and p-type transistors. Research on atomically thin electronics has produced promising n-type materials, but p-type performance and scalable growth have remained harder to achieve. That imbalance makes it difficult to build a complete 2D analogue of complementary logic at manufacturing-relevant dimensions.
BCN is interesting because this work combines three requirements that rarely arrive together: atomically thin geometry, strong p-type transport and wafer-scale epitaxial growth. If the material and process prove compatible with practical semiconductor fabrication, they could provide a p-channel component for complementary 2D circuits rather than forcing designers to depend on small exfoliated flakes or less scalable material combinations.
Possible applications
The clearest long-term target is complementary 2D electronics, including low-power logic and monolithic three-dimensional integration in which active transistor layers are stacked vertically. Atomically thin channels are particularly attractive for such architectures because their small thickness may help control electrostatics while reducing the vertical space occupied by each device layer.
The result is also a useful materials-design demonstration. It shows how precursor chemistry and substitutional carbon incorporation can turn a boron-nitride-derived monolayer into a useful semiconductor, suggesting a broader route for tuning electronic properties in chemically related 2D materials.
Development stage and limitations
This is an experimental research result, not a production-ready replacement for silicon CMOS. The reported devices demonstrate impressive transistor metrics and wafer-scale material growth, but commercial integration would require considerably more work. Among the questions still to be addressed are manufacturing yield at larger wafer sizes, long-term device and environmental stability, contact resistance, reproducibility across independent laboratories, compatibility with industrial process temperatures and dielectrics, and the performance of complete complementary circuits rather than individual p-channel devices.
The two-inch demonstration is therefore best viewed as an important scaling milestone. It moves BCN beyond a small-flake materials experiment, but it does not by itself establish a semiconductor manufacturing process.
Primary sources
Peer-reviewed paper: Chien-Chih Tseng et al., “Wafer-scale epitaxy growth of high-mobility p-type boron carbon nitride,” Nature (published 30 September 2026). DOI: 10.1038/s41586-026-11047-9.
University research announcement: University of Tokyo School of Engineering, 1 October 2026: High-performance p-type two-dimensional semiconductor realized at wafer scale.
Element Folio note: Performance values above are reported by the research team and should be interpreted as laboratory device results until independently reproduced and demonstrated in integrated circuits.
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