Researchers at the Georgia Institute of Technology and Tianjin University have developed a method to fabricate semiconductors using graphene. The process potentially paves the way for a new class of high-performance electronic devices that may surpass the capabilities of traditional silicon-based semiconductors. The team led by Georgia Tech's Regents' Professor of Physics Walter de Heer, has published their findings in the ‘Nature' journal, unveiling how their novel approach creates a semiconductor with a substantial bandgap.
Bandgap Breakthrough
Graphene, a one-atom-thick layer of carbon atoms arranged in a hexagonal lattice, has long enchanted scientists with its remarkable electron mobility—a measure of how quickly electrons can move through a material—compared to silicon. The obstacle, however, was that graphene did not inherently possess a bandgap, which is essential for electronic applications to control the flow of electricity.
The newfound graphene semiconductor boasts a bandgap of 0.6 eV, sufficient for practical application in electronics. The team has leveraged a process called quasi-equilibrium annealing to form ‘epigraphene', a version of graphene that spontaneously forms on silicon carbide surfaces when silicon is stripped away at high temperatures. The researchers innovatively sandwiched a silicon surface atop a carbon surface between two SiC wafers, inducing carbon atoms to migrate and form a semiconducting layer attached to the SiC substrate.
Terahertz Technology and Future Prospects
The significance of this advancement lies not only in surpassing other 2D semiconductors in electron mobility but also in the prospects of integrating semiconducting graphene with its metallic counterpart. This has the potential to significantly reduce device resistance and enable far smaller electronic components than currently possible.
In addition to the high mobility benefits, the graphene semiconductor might be instrumental in developing devices operable in the Terahertz frequency range of the electromagnetic spectrum, an area with considerable promise for future communications technologies, including visions for 6G.
The next challenge for the team lies in scaling up the production process to ensure commercial viability. While there are no apparent major challenges in producing the material in wafer scales up to 1 inch, the complete development lifecycle from such a revolutionary proof-of-concept to market availability could be extensive.
De Heer compares the current stage of their graphene semiconductor development to the era of the Wright brothers' first flight, indicating that as with aviation history, the trajectory from groundbreaking discovery to widespread commercial application could span several years or decades. With semiconducting graphene's potential to be significantly impactful, stakeholders in the electronics industry may eagerly anticipate its evolution into an industry-changing technology.
2023 Breakthroughs in Graphene and New Materials Research
Last year was pivotal in the ongoing research and development of graphene and other innovative materials. In May, MIT developed atom thin CPUs that have the potential to revolutionize the computing industry. MIT engineers have developed a breakthrough technique that can grow 2D materials directly on top of silicon wafers, without damaging them. The technique, reported in a paper published in Nature on January 18, 2023, uses a low-temperature process that deposits atoms on a wafer coated with a “mask” that guides the growth of the 2D layers.
In November, Google DeepMind leveraged AI to create GNoME, a model that has successfully predicted 2.2 million potential new inorganic crystal structures, a monumental stride that could significantly impact the production of cutting-edge microprocessors, electric batteries, solar panels, and other technologies.
