If computer chips could be built from semiconductors just one atom thick, they could pack far more transistors into a smaller space while using lesspower. So far, however, the technology has been held back by the weakness of “p-type” transistors, which make up half of every modern chip.
In a new study published in Nature, researchers led by Vincent Tung at the University of Tokyo have shown that atom-thin sheets of boron carbon nitride (BCN) could offer a promising solution.
Transistor bottleneck
Today’s chips rely on two types of transistors working in pairs. In “n-type” transistors, electric current is carried by negatively charged electrons. In “p-type” transistors, it is carried by holes: vacancies left behind when electrons are missing from the material, which move around like positive charges.
Researchers have found several atom-thin materials that carry electrons very well, but finding counterparts that carry holes just as well has proven far harder, creating a bottleneck for the whole technology. Many candidate materials so far have involved trade-offs: They conduct poorly, break down in air or heat or are difficult to make on large scales.
Semiconducting wafer
Tung’s team tackled this problem by replacing some nitrogen atoms in boron nitride, an atom-thin insulator with a honeycomb structure, with carbon.
To prevent the carbon atoms from clumping together, the researchers used two vapor-based ingredients: one that steadily supplied boron and nitrogen and another that released its carbon slowly. This “epitaxy” approach allowed them to grow wafer-sized films of BCN, including on patterned silicon chips.
After examining the films’ structure using atomic-resolution microscopy, they built and tested 224 transistors under everyday conditions. Their results showed that carbon atoms had spread evenly through the material, mostly replacing nitrogen. Since carbon has one fewer outer electron than nitrogen, each swap left a hole behind.
Crucially, the material’s honeycomb structure stayed almost undisturbed, so these holes could flow freely. As a result, the transistors combined strong currents with clean switching: Their “on” currents were 100 million times larger than their “off” currents. Most of the devices even surpassed performance targets the chip industry aims to reach by 2031, and the material stayed stable in air.
Toward atom-thick transistors
Tung’s team now hopes their results will help pave the way for chips that pair atom-thin n-type and p-type transistors, potentially stacked in layers. Since the metal contacts connecting the BCN to its surrounding wiring were not yet optimized, further improvements to these contacts could boost performance even more.
Other steps will include shrinking the transistors and lowering the 1,000°C (1,832°F) temperature required for the material’s growth, which could damage underlying components. If these challenges can be overcome, the technology could become scalable enough for commercial rollout. https://techxplore.com/news/2026-10-atom-thin-material-key-transistor.html
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