Graphene’s electrical properties transformed by layer alignment

Researchers at the University of California, Riverside, have made a rather interesting accidental discovery about the electrical properties of graphene, a lattice-like arrangement of carbon atoms that has been tapped as a potential replacement for silicon in future microprocessors. Graphene’s high conductivity makes it particularly attractive for such applications, but the lack of a “band gap,” which would allow transistors to be turned off, presents a challenge.

When layering three graphene sheets, the researchers observed a dramatic change in the electrical properties of the material. Shifting the alignment of the top layer in the three-sheet stack by just one atom transformed the material from a conductor to an insulator, effectively creating a band gap that is now the focus of their studies. Jeanie Lau, the associate professor of physics and astronomy whose lab is responsible for the finding, likens it to discovering a tuning knob for the material. Lau isn’t sure what causes the dramatic shift in electrical properties, though. Her team’s findings have been published by Nature Physics.

This isn’t the first time a band gap has been created with graphene. Last year, IBM researchers created a band gap in two-layer graphene by applying an external electric field.  A few years before that, Berkley Labs observed a band gap in a similar graphene structure that had been chemically doped.

Graphene’s material properties hold much promise, but what about actually building the lattice structures in large volumes? Researchers at MIT are developing an “industrial-scale printing press” designed to churn out graphene sheets as large as one square kilometer. The previous record is reportedly only one square foot, so their work is certainly cut out.

Comments closed
    • AGerbilWithAFootInTheGrav
    • 8 years ago

    [url<]http://www.bbc.co.uk/news/technology-13886438[/url<] [quote<] IBM made early inroads in 2010 when it created a basic graphene transistor. This month, the company announced that it had gone a step further, integrating it into a circuit known as a broadband frequency mixer - an essential component of TVs, mobile phones and radios. Integrated circuit with a graphene transistor First-ever integrated circuit with a graphene transistor "When a radio station broadcasts at a high frequency through space, the wave is then received by your radio, but the high frequency cannot be heard, so it must be converted into a low frequency wave that we can hear," the lead scientist of the project, Dr Phaedon Avouris, told BBC News. IBM calls its research an important milestone for the future of wireless devices. Perhaps more importantly, it demonstrates the capability of graphene integrated circuits. . I never suspected we would get there so fast," said Dr Konstantin Novoselov of Manchester University. He is the man who, together with a colleague Dr Andre Geim, discovered this highly conductive, extremely strong and transparent material in 2004. The two scientists, both originally from Russia, managed to extract graphene while experimenting with plain old sticky tape and graphite, commonly used in pencils. The pair won the prestigious Nobel Prize for their breakthrough. "This integrated circuit is a logical step forward, and it's somewhere in the middle between the first experiments and real-life applications," said Dr Novoselov. "But I was surprised to see that someone managed to do it that quickly.[/quote<] a month old but should be relevant...

    • A_Pickle
    • 8 years ago

    [quote<]Researchers at MIT are developing an "industrial-scale printing press" designed to churn out graphene sheets as large as one square kilometer.[/quote<] O_O GOD BLESS THESE PEOPLE. One [i<]square kilometer[/i<]? Jesus, if they're able to make it that large at a reasonable price, we'll probably be able to solve every social problem ever in less than ten hours...

      • OneArmedScissor
      • 8 years ago

      Yeah, when it kills everyone.

        • sweatshopking
        • 8 years ago

        BECAUSE WE ARE A DANGER TO OURSELVES. I’VE SEEN THIS MOVIE

          • no51
          • 8 years ago

          MAN IS THE MOST DANGEROUS BEAST OF ALL

            • stupido
            • 8 years ago

            just look in the mirror… 😀

        • Johnny5
        • 8 years ago

        If it means they make a movie with The Graphene Sheet vs. The Blob, I’m all for it.

        • Bensam123
        • 8 years ago

        Asbestos is the savior and will solve all heating related problems!

      • kamikaziechameleon
      • 8 years ago

      I assume that is a typo but if they do have a legit 1 Km process, HOLY COW

        • mesyn191
        • 8 years ago

        They’re working on it they don’t have one yet. The thing is they’ve been working on mass produced graphene for years. Holding your breath at this point for one is likely a bad idea.

          • MadManOriginal
          • 8 years ago

          Stuff like this always takes years unless you just read very mainstream or popular media. Carbon *will* be the next major building block of electronics in one way or another, to know this all you have to do is look at column 4A of the periodic table and know what elements transistors have been composed of in the past.

        • willmore
        • 8 years ago

        It probably just means that it’s a continuous process and you can print as much as you can fit on a roll. So, on 1km^2 is sort or arbitrary. Now, if they could make one that is a sqaure one km on a side, that would be cool. Questionably useful, but cool.

          • yogibbear
          • 8 years ago

          would you be able to see it though? 1 atom thick… 1km2….

    • Farting Bob
    • 8 years ago

    Everytime graphene is discussed in a CPU sense it seems like the wonderdrug that will leak almost nothing, scale to 100Ghz while being cheap to make. Ive been hearing this for years. Where is my Intel Graphene i9000, base clocked at 50Ghz with turbo boost of 80Ghz, all for under $200??

      • thanatos355
      • 8 years ago

      It’s Intel you’re talking about. They’ll throw an “Extreme” on there and hang a $1,000 price tag around it’s neck.

        • thanatos355
        • 8 years ago

        I question you gentlemen’s sense of humor.

          • Bensam123
          • 8 years ago

          Thumbs down don’t have a sense of humor.

      • yogibbear
      • 8 years ago

      It probably needs investment in R&D and production techniques that requires the sort of cashflow/money injection that only something like trying to get to travel to another planet, or world war 3, or something else that drastically increases the processing power required for large scale efforts would enable.

      • A_Pickle
      • 8 years ago

      It’s probably closer than it’s ever been. I imagine that we’re much closer to being able to use graphene for semiconductors than we are to being able to use it for space elevators. And, to be honest, I could care less about my Intel Graphene i9000 — I want a damn space elevator. Six silicon cores gives me [i<]plenty[/i<] of performance.

      • Vulk
      • 8 years ago

      The whole point about the band gap issue, is that they COULDN’T make traditional planar transistors using it until that was solved. As a potential substance to make ICs with, it sounds great, but it’s a pain to use, it’s still pretty poorly understood, and because no one is using it, anyone who makes the shift first will have to go through all the growing pains, do all the hard work, make all the mistakes, and some other Fab will then match them within a year or two, and that’s AFTER things like the ability to create band gaps by taking a separate sheet that’s an atom thicker are actually understood and the implications are figured out.

      Graphene has a long way to go. And the first graphene processors will suck in comparison to traditional silicon based ones, just because the expertise and tricks we’ve learned with the current technology won’t easily transfer over.

      So keep dreaming about the i9000, it will more than likely happen eventually, but we’re still years away from seeing that tech going into production, let alone being commercially viable, or faster than silicon.

        • Geistbar
        • 8 years ago

        To add to what Vulk said, graphene is at a point where many potentially wonderful technologies get “stuck”. It has major problems attached to it, making it unusable in the present. Companies can not just shift over their R&D entirely to it, of course, and usually such problems are difficult to “brute force”; throwing $10 billion at it might get the problem solved barely faster than throwing $100 million at it. As well, the companies still need to make products [i<]now[/i<], so shifting all their brightest minds over to something that is unproven is nonviable for them. Essentially, if you want to see things that use potentially ground breaking things such as this, you need to hope for more research institutions that are like the Bell Labs of decades past. Even that will not make these things happen magically, but it should speed up the process a decent bit.

          • mesyn191
          • 8 years ago

          Yea but most no one does the blue sky R&D they did anymore on a mass scale. All the major corps are focused on the quarterly or perhaps yearly bottom line. They want the government funded or assisted universities to do all that R&D for them now and they want the government/uni’s to practically give away the patents for nothing too. To say that this whole situation is not conducive to the necessary long term research that is needed is a vast understatement at this point.

            • Geistbar
            • 8 years ago

            I agree, I did not mean to imply that such research institutions are easy to create. I wish it was an easy problem to solve, but anything that requires lots of money is going to be politically divisive. Maybe Bell Labs was just a fluke of its era, and not something we can reasonably expect to replicate. Hopefully not, I know at least Intel, Microsoft and IBM have their own long term research divisions, but I do not know how big they are, people or money wise. And those all have the issue of being focused on things that are likely to be highly profitable.

            • NeelyCam
            • 8 years ago

            Bell Labs was a result of the time when massive government funding was readily available for anything imaginable. When cost-effectiveness became important, the whole place imploded.

            Bell Labs like institutions have since been replaced with more distributed efforts. Various companies are funding IMEC and a lot of university research through coordinating organizations such as SRC.

            • willmore
            • 8 years ago

            Bell Labs was the result of an unregulated monopoly having all the money they chose to print to invest in gestating technologies to ensure that they would stay in control of everything. It died when it was forced to justify the spending that had been put into it.

            • NeelyCam
            • 8 years ago

            No argument here.

        • MadManOriginal
        • 8 years ago

        The first manufacturer to move beyond silicon which have huge, nay MASSIVE, advantages. We’ve seen the patent wars heat up over the last 10-15 years (basically dot.com on) but that will be nothing compared to the first mover in carbon-based large scale manufacturing. Of course if China’s economy has ‘taken over’ at that point then IP won’t matter at all.

          • bthylafh
          • 8 years ago

          IP will matter again when China’s economy takes over – they’ll simply follow our footsteps and have a robust IP/patent/trademark/copyright system once they’ve got enough of their own to worry about. Right now they don’t because so much of what they’ve got comes from foreign sources, just as we didn’t at first.

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