Tokyo, Japan – Many modern electronic circuits depend on both n-type transistors, which conduct current through electrons, and p-type transistors, which conduct current through positively charged holes. Although high-performance n-type two-dimensional (2D) semiconductors have advanced rapidly, comparable p-type materials that can be grown over large areas remain scarce. This imbalance is a major obstacle to developing complementary 2D electronics. Now, an international research team has developed an atomically thin p-type semiconductor and demonstrated its growth across a 2-inch wafer.
Researchers at the Graduate School of Engineering, The University of Tokyo, working with collaborators in Japan and Taiwan, incorporated carbon into normally insulating boron nitride (BN) to create p-type boron carbon nitride (BCN). Their study, published in Nature , reports the epitaxial growth of a continuous single-layer BCN film on copper (111) and promising transistor performance. The findings connect atomic-scale material design with wafer-scale synthesis.
Boron nitride consists of an ordered, hexagonal network of boron and nitrogen atoms and is normally an electrical insulator. By incorporating carbon atoms and carbon pairs into this lattice, the researchers engineered p-type semiconducting behavior. Atomic-resolution microscopy revealed a continuous but locally distorted crystal lattice, with carbon appearing to preferentially substitute for nitrogen in the regions examined. Spectroscopic measurements confirmed an electronic bandgap of approximately 1.90 eV. This approach draws on the same broad principle as doping silicon: changing the atomic composition to tailor silicon’s electronic properties.
“By controlling how carbon atoms are inserted into the boron nitride lattice, we can engineer its electronic properties at the atomic scale,” says Vincent Tung, a corresponding author of the study. “Our approach allows us to create a material that conducts electricity efficiently while preserving the ordered structure needed for high-performance electronic devices.”
The growth mechanism relies on two molecular precursors: monomethyl ammonia borane (MMAB) and ammonia borane (AB). By engineering their dehydrogenation and surface-reaction pathways, the researchers overcame a critical challenge in BCN synthesis: the spatial and temporal mismatch in the supply of boron-, carbon-, and nitrogen-containing species to the growth surface. This coordinated delivery suppresses the formation of carbon-rich regions and promotes carbon incorporation into the boron nitride lattice. As a result, the team achieved continuous, monolayer p-type BCN growth across a 2-inch wafer.
“An important aspect of this work is demonstrating that atomic-level engineering and wafer-scale synthesis can go hand in hand,” explains Tung. “We have developed a growth strategy that produces uniform, high-quality BCN over an entire wafer, while also achieving the electronic properties needed for high-performance transistors.”
To evaluate device performance and reproducibility, the researchers characterized 224 BCN field-effect transistors made from three separate growth batches. These p-type devices showed a field-effect hole mobility of approximately 100 cm² V⁻¹ s⁻¹, an on-current exceeding 0.9 mA per micrometer of channel width, and an on/off current ratio of about 10⁸. The distribution of measurements across the wafer and batches supports the uniformity of the process. These results highlight BCN’s potential to complement n-type 2D semiconductors in electronic circuits, although a complete complementary circuit has not yet been demonstrated.
This work establishes a promising wafer-scale p-type 2D semiconductor platform for future complementary electronic circuits and monolithic three-dimensional (3D) integration. The team’s future research will focus on refining control over carbon substitution, lowering growth temperatures, integrating BCN with n-type devices, and, ultimately, developing manufacturing-ready processes.
###
The article, “Wafer-scale epitaxy growth of high-mobility p-type boron carbon nitride,” was published in Nature (2026).
DOI: 10.1038/s41586-026-11047-9
This work was supported by JSPS KAKENHI (JP23H00253, JP24K21233, JP25KF0196 and JP26H02218), JST CREST, Japan (JPMJCR24A3), and JST ASPIRE, Japan (JPMJAP2531).
Nature
Experimental study
Not applicable
Wafer-scale epitaxy growth of high-mobility p-type boron carbon nitride
30-Sep-2026