Silicon has long been the cornerstone of semiconductor technology, powering everything from smartphones and computers to electric vehicles. However, this reigning material may soon face significant competition as researchers develop new alternatives that could transform electronics in the coming years.

A research team at Penn State has successfully built a computer capable of performing simple operations using two-dimensional (2D) materials instead of silicon. These 2D materials are not only thinner at the atomic scale but also maintain their electronic properties even when scaled up, offering promising advantages over traditional silicon.

The team created a complementary metal-oxide-semiconductor (CMOS) computer without relying on silicon. Instead, they utilized molybdenum disulfide to fabricate n-type transistors and tungsten diselenide for p-type transistors, combining these two types to produce functional circuits. This approach tackles a major challenge in replacing silicon, since CMOS technology requires both n-type and p-type semiconductors to work together efficiently while consuming low power.

While previous attempts at using 2D materials successfully demonstrated small circuits, scaling this up to a fully functional computer had remained elusive—until now. By leveraging metal-organic chemical vapor deposition (MOCVD), the researchers grew large-area sheets of molybdenum disulfide and tungsten diselenide and fabricated over a thousand transistors of each type. Careful tuning of the fabrication and post-processing steps allowed precise adjustment of transistor thresholds, enabling fully operational CMOS logic circuits.

The resulting 2D CMOS computer operates at low supply voltages with minimal power consumption and can perform basic logic functions at frequencies up to 25 kilohertz. Although its speed is slower compared to silicon-based CMOS circuits, the device demonstrates the viability of 2D materials in computer architectures. A computational model developed alongside the experiments helped benchmark this new technology against existing silicon systems, highlighting potential pathways for optimization.

This achievement represents a significant step forward in harnessing 2D materials to advance electronics, though more research is needed before such computers can be widely adopted. Silicon technology has benefited from nearly 80 years of development, while research into 2D materials is relatively young, dating back only to around 2010. The transition to 2D-based computing is expected to be gradual but marks an important leap compared to the historical progression of silicon.

The work was supported by the 2D Crystal Consortium Materials Innovation Platform at Penn State, providing critical facilities and tools that enabled this breakthrough in semiconductor research.

By Impact Lab