Researchers at the Georgia Institute of Technology, led by Walter de Heer, have created the world’s first functional semiconductor made from graphene. This breakthrough could lead to smaller, faster electronic devices and has potential applications for quantum computing. The graphene semiconductor is compatible with conventional microelectronics processing methods, making it a viable alternative to silicon, which is nearing its limit. The team’s graphene semiconductor has 10 times the mobility of silicon, meaning electrons move with very low resistance, leading to faster computing. The research was published in the journal Nature.
Georgia Tech Researchers Develop Graphene-Based Semiconductor
Researchers at the Georgia Institute of Technology (Georgia Tech) have developed the world’s first functional semiconductor made from graphene, a single sheet of carbon atoms. This breakthrough could revolutionize the electronics industry, as semiconductors are essential components of electronic devices. The team’s discovery comes at a time when silicon, the primary material used in modern electronics, is reaching its limit due to the demand for faster computing and smaller devices.
The research team, led by Walter de Heer, Regents’ Professor of Physics at Georgia Tech, included researchers from Atlanta, Georgia, and Tianjin, China. They successfully produced a graphene semiconductor that is compatible with conventional microelectronics processing methods, a critical requirement for any viable alternative to silicon.
Overcoming the Band Gap Challenge
The team’s research, published in Nature, addresses a significant challenge that has hindered graphene research for years: the “band gap”. This electronic property allows semiconductors to switch on and off, a feature that graphene lacked until now.
De Heer and his team have now created a robust graphene semiconductor with 10 times the mobility of silicon, and unique properties not found in silicon. This achievement is the result of a decade-long effort to make the material good enough to work in electronics.
The Journey to a New Semiconductor
De Heer began exploring carbon-based materials as potential semiconductors early in his career, and switched to 2D graphene in 2001. He was motivated by the hope of introducing three special properties of graphene into electronics: its robustness, its ability to handle large currents, and its resistance to heating up and falling apart.
The team achieved a breakthrough when they figured out how to grow graphene on silicon carbide wafers using special furnaces. They produced epitaxial graphene, a single layer that grows on a crystal face of the silicon carbide. When made properly, the epitaxial graphene chemically bonded to the silicon carbide and started to show semiconducting properties.
Collaboration and Persistence
Over the next decade, the team continued to perfect the material at Georgia Tech and later in collaboration with colleagues at the Tianjin International Center for Nanoparticles and Nanosystems at Tianjin University in China. De Heer founded the center in 2014 with Lei Ma, the center’s director and a co-author of the paper.
The Making of a Functional Transistor
In its natural form, graphene is a semimetal, not a semiconductor. To make a functional transistor, a semiconducting material must be greatly manipulated, which can damage its properties. To prove that their platform could function as a viable semiconductor, the team needed to measure its electronic properties without damaging it.
They used a technique called doping, where atoms are put on the graphene that “donate” electrons to the system. This technique worked without damaging the material or its properties. The team’s measurements showed that their graphene semiconductor has 10 times greater mobility than silicon, meaning the electrons move with very low resistance, which translates to faster computing.
The Future of Electronics
The team’s product is currently the only two-dimensional semiconductor that has all the necessary properties to be used in nanoelectronics, and its electrical properties are far superior to any other 2D semiconductors currently in development.
Epitaxial graphene could cause a paradigm shift in the field of electronics and allow for completely new technologies that take advantage of its unique properties. The material allows the quantum mechanical wave properties of electrons to be utilized, which is a requirement for quantum computing.
According to de Heer, it is not unusual to see yet another generation of electronics on its way. Before silicon, there were vacuum tubes, and before that, there were wires and telegraphs. Silicon is one of many steps in the history of electronics, and the next step could be graphene.
“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. “But the story of our work for the past 10 years has been, ‘Can we get this material to be good enough to work?'”
“We were motivated by the hope of introducing three special properties of graphene into electronics,” he said. “It’s an extremely robust material, one that can handle very large currents, and can do so without heating up and falling apart.”
“It’s like driving on a gravel road versus driving on a freeway,” de Heer said. “It’s more efficient, it doesn’t heat up as much, and it allows for higher speeds so that the electrons can move faster.”
“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 Ma. “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.”
“Our motivation for doing graphene electronics has been there for a long time, and the rest was just making it happen,” de Heer said. “We had to learn how to treat the material, how to make it better and better, and finally how to measure the properties. That took a very, very long time.”
“To me, this is like a Wright brothers moment,” de Heer said. “They built a plane that could fly 300 feet through the air. But the skeptics asked why the world would need flight when it already had fast trains and boats. But they persisted, and it was the beginning of a technology that can take people across oceans.”
Georgia Tech Innovation Summary
Researchers at the Georgia Institute of Technology have developed the world’s first functional semiconductor made from graphene, a material that could potentially replace silicon in electronics due to its superior conductivity and robustness. This breakthrough could pave the way for smaller, faster electronic devices and has potential applications in quantum computing.
- Researchers at the Georgia Institute of Technology have created the world’s first functional semiconductor made from graphene, a single sheet of carbon atoms. This could lead to smaller, faster electronic devices and has potential applications for quantum computing.
- The team, led by Walter de Heer, Regents’ Professor of Physics at Georgia Tech, overcame a significant hurdle in graphene research – the lack of a “band gap”, a crucial electronic property that allows semiconductors to switch on and off.
- The graphene semiconductor is compatible with conventional microelectronics processing methods, making it a viable alternative to silicon, which is reaching its limit due to the demand for faster computing and smaller devices.
- The graphene semiconductor has 10 times the mobility of silicon, meaning electrons move with very low resistance, leading to faster computing.
- The team’s product is currently the only two-dimensional semiconductor with all the necessary properties for use in nanoelectronics, and its electrical properties are superior to any other 2D semiconductors currently in development.
- The research was conducted in collaboration with colleagues at the Tianjin International Center for Nanoparticles and Nanosystems at Tianjin University in China, which de Heer founded in 2014 with Lei Ma, the center’s director and a co-author of the paper.
- The research was published in the scientific journal Nature.