Silicon has enabled advancements in semiconductor technology through miniaturization, but scaling challenges necessitate the exploration of new materials. Two-dimensional (2D) materials, with their atomic thickness and high carrier mobility, offer a promising alternative. In a world first, researchers at Penn State used 2D materials to develop a computer capable of simple operations.
This conceptual illustration of a computer based on 2D molecules displays an actual scanning electron microscope image of the computer fabricated by Ghosh et al. Image credit: Krishnendu Mukhopadhyay / Penn State.
“Silicon has driven remarkable advances in electronics for decades by enabling continuous miniaturization of field-effect transistors (FETs),” said Penn State Professor Saptarshi Das.
“FETs control current flow using an electric field, which is produced when a voltage is applied.”
“However, as silicon devices shrink, their performance begins to degrade.”
“Two-dimensional materials, by contrast, maintain their exceptional electronic properties at atomic thickness, offering a promising path forward.”
In their complementary metal-oxide semiconductor (CMOS) computer, Professor Das and colleagues used two different 2D materials to develop both types of transistors needed to control the electric current flow: molybdenum disulfide for n-type transistors and tungsten diselenide for p-type transistors.
“CMOS technology requires both n-type and p-type semiconductors working together to achieve high performance at low power consumption — a key challenge that has stymied efforts to move beyond silicon,” Professor Das said.
“Although previous studies demonstrated small circuits based on 2D materials, scaling to complex, functional computers had remained elusive.”
“That’s the key advancement of our work. We have demonstrated, for the first time, a CMOS computer built entirely from 2D materials, combining large area grown molybdenum disulfide and tungsten diselenide transistors.”
The researchers used metal-organic chemical vapor deposition (MOCVD) — a fabrication process that involves vaporizing ingredients, forcing a chemical reaction and depositing the products onto a substrate — to grow large sheets of molybdenum disulfide and tungsten diselenide and fabricate over 1,000 of each type of transistor.
By carefully tuning the device fabrication and post-processing steps, they were able to adjust the threshold voltages of both n- and p-type transistors, enabling the construction of fully functional CMOS logic circuits.
“Our 2D CMOS computer operates at low-supply voltages with minimal power consumption and can perform simple logic operations at frequencies up to 25 kilohertz,” said Subir Ghosh, a doctoral student at Penn State.
“The operating frequency is low compared to conventional silicon CMOS circuits, but our computer — known as a one instruction set computer — can still perform simple logic operations.”
“We also developed a computational model, calibrated using experimental data and incorporating variations between devices, to project the performance of our 2D CMOS computer and benchmark it against state-of-the-art silicon technology.”
“Although there remains scope for further optimization, this work marks a significant milestone in harnessing 2D materials to advance the field of electronics.”
The team’s work was published this month in the journal Nature.
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S. Ghosh et al. 2025. A complementary two-dimensional material-based one instruction set computer. Nature 642, 327-335; doi: 10.1038/s41586-025-08963-7
