Researchers Develop First-Ever Functional Graphene Semiconductor

In the 21st century, the pursuit is to develop electronic devices that are both smaller and faster, whether for applications in the medical sector or robotics.

Experts have been busy working on producing advanced materials for modern electronic devices to meet this escalating demand. 

Now, a significant milestone in this endeavor has been achieved by a team of researchers at the Georgia Institute of Technology, who have successfully engineered the world’s first functional semiconductor using graphene.

“To me, this is like a Wright brothers moment,” said Walter de Heer, Regents’ Professor of Physics at Georgia Techde, who led this development.  Interestingly, this newly built tech could be used to advance quantum computing.

A potential replacement for silicon

Graphene is a two-dimensional honeycomb-like structure formed by a single layer of carbon atoms organized in a hexagonal lattice. It is well-known for having exceptional qualities, including strong electrical conductivity, mechanical strength, and flexibility.

“It’s an extremely robust material, one that can handle very large currents and can do so without heating up and falling apart,” said de Heer. 

Semiconductors are materials that exhibit electrical conductivity under particular conditions.

This innovation holds great importance in the electronics industry, considering that the commonly used silicon material is nearing its limits in the face of increased demand for quicker processing and smaller electronic devices.

Georgia Tech’s graphene semiconductor has the potential to emerge as a viable substitute for silicon in the years ahead. According to the press release, the semiconductor is compatible with “conventional microelectronics processing methods.”

“We now have an extremely robust graphene semiconductor with 10 times the mobility of silicon, and which also has unique properties not available in silicon,” de Heer said. 

The development of the material

De Heer and his colleagues accomplished this by inventing a method for growing graphene on silicon carbide wafers using specialized furnaces. 

As a result, epitaxial graphene—a single layer clinging to silicon carbide’s crystal face—was formed. The researchers proved that epitaxial graphene chemically binds to silicon carbide, demonstrating semiconducting characteristics, after extensive testing.

The scientists also used a technique called doping to test the material’s conductivity. Their experiments revealed that this novel graphene semiconductor has 10 times the mobility of silicon.

Key band gap challenge

However, achieving this breakthrough was challenging; the team faced a major obstacle in graphene research—the absence of a “band gap.” 

This critical electronic feature is essential for semiconductors to switch on and off effectively and is a basic aspect of electronic performance.

Until this development, graphene lacked a band gap.

“A long-standing problem in graphene electronics is that graphene didn’t have the right band gap and couldn’t switch on and off at the correct ratio,” said Lei Ma, director of Tianjin International Center for Nanoparticles and Nanosystems at Tianjin University in China, in a press release.

“Over the years, many have tried to address this with a variety of methods. Our technology achieves the band gap and is a crucial step in realizing graphene-based electronics,” Ma, a co-author of this study, added. 

This achievement marks a paradigm shift in the field of electronics, paving the way for a new era of technologies harnessing the extraordinary capabilities of graphene.

The research was published in the journal Nature on January 3.