First-Ever Non-Silicon 2D Computer Developed Using Atomic-Scale Materials

A team of researchers from Pennsylvania State University has utilized two-dimensional (2D) materials, each just a single atom thick, to create a computer capable of performing basic tasks. According to them, this advancement marks a significant step toward the development of thinner, faster, and more energy-efficient electronics.

The researchers engineered a complementary metal-oxide-semiconductor (CMOS) computer without relying on silicon. Instead, they employed two distinct 2D materials to develop the two types of transistors necessary for controlling electric current in CMOS computers: molybdenum disulfide for n-type transistors and tungsten diselenide for p-type transistors.

«Silicon has driven remarkable progress in electronics for decades, enabling the continuous miniaturization of field-effect transistors (FET),» stated Saptarshi Das, a professor of engineering and mechanics at Penn State, who led the study. FETs control current through an electric field induced by applied voltage. «However, as silicon devices become smaller, their performance starts to decline. In contrast, two-dimensional materials maintain their exceptional electronic properties even at atomic thickness, presenting a promising path forward,» he elaborated.

Das explained that CMOS technology necessitates both n-type and p-type semiconductors, a crucial challenge that has hindered efforts to move beyond silicon. While earlier research demonstrated small circuits made with 2D materials, scaling them up to complex functional computers has proven to be a difficult task, he noted.

«We are the first to showcase a CMOS computer entirely constructed from 2D materials that integrates molybdenum disulfide and tungsten diselenide transistors on a large scale,» Das announced. The team employed a metal-organic chemical vapor deposition (MOCVD) method—a fabrication process that involves vaporizing materials, facilitating a chemical reaction, and depositing the products on a substrate—to grow both molybdenum disulfide and tungsten diselenide, producing over 1,000 transistors of each type. By meticulously optimizing the device fabrication and post-processing stages, they were able to adjust the threshold voltages of both n-type and p-type transistors, allowing for the creation of fully functional CMOS logic circuits.

«Our 2D computer operates at low voltage with minimal power consumption and can execute simple logic operations at frequencies of up to 25 kilohertz,» noted Subir Ghosh, one of the developers.

He mentioned that this operational frequency is lower compared to conventional silicon CMOS circuits. «We have also developed a computational model calibrated using experimental data that accounts for device variations to predict the performance of our 2D computer and compare it with current silicon technologies,» Ghosh added.

Das remarked, “Silicon technology has been under development for about 80 years, while research into 2D materials is relatively recent, with significant advancements only beginning around 2010.”

Meanwhile, the Australian company Cortical Labs has introduced the CL1 system, also known as “synthetic biological intelligence” (SBI). This innovation represents the world’s first «biological computer,» which combines human brain cells with silicon hardware to create neural networks.