Konstantin Novoselov
From the Special Topic of
Graphene
According to our Special Topics analysis on graphene
research over the past decade, the scientist whose work
ranks at #1 by total cites is Dr. Kostya Novoselov, with 33
papers cited a total of 2,895 times. He also ranks at #6 by
number of papers and #2 by cites per paper. Five of his
papers appear on the lists of the most-cited papers over
the past decade and over the past two years.
InEssential Science IndicatorsSMfrom
Clarivate, Dr.
Novoselov's record includes 49 papers, largely classified in Physics and
Materials Science, cited 3,536 times between January 1, 1998 and October
31, 2008. Dr. Novoselov is a Royal Society Research Fellow in School of
Physics & Astronomy at the University of Manchester.
Below,
ScienceWatch.com correspondent Gary Taubes talks with
Dr. Novoselov about his pioneering work with
graphene.
Considering that graphene physics is an
entirely new field of science, how did you get into it?
My background is in mesoscopic physics, studying fairly macroscopic objects
that show some quantum effects. I did my Ph.D. with
Andre Geim—first in Holland—and when he moved
to the UK he invited me here as a post-doc. The style of Geim's lab
(which I'm keeping and supporting up to now) is that we devote ten
percent of our time to so-called "Friday evening" experiments. I just do
all kinds of crazy things that probably won’t pan out at all, but
if they do, it would be really surprising. Geim did frog levitation as
one of these experiments, and then we did gecko tape together. There are
many more that were unsuccessful and never went anywhere (though I still
had a good time thinking about and doing those experiments, so I love
them no less than the successful ones).
This graphene business started as that kind of Friday evening experiment.
We weren’t hoping for much, and when I gave it to a student, it
initially failed. Then we had what you could call a stream of coincidences
that basically brought us some very remarkable results quite
quickly—within a week or so. Then we decided to continue on a more
serious basis.
What was the original idea behind the graphene
experiment?
"Considering that the field is only
four years old, we’ve made enormous
progress."
Well, people talk about metal electronics a lot, substituting
semiconductors for metal. There are many advantages to that, but nobody had
really used graphite as a material for electronics. So we decided to see if
that was possible. Basically, the idea was that we needed to get some very
thin films of high-quality graphite; one of our students did it the first
time by trying to file down thick graphite crystals and it didn’t
work. We almost gave up after that.
At the same time we had a very experienced guy—Oleg
Shkliarevskii—working here, building a low-temperature scanning
tunneling microscope. He showed how the samples were prepared for an STM.
The best sample is graphite—you can quite easily gain atomic
resolution there. They clean graphite surface by peeling the top layer off
with Scotch tape. It is a very standard technique, used everywhere. We knew
about the method before, but everything is good in its own time, so one
glance at it and we knew—that must be it. I tried it and within a few
days we had a working device.
So this was serendipity, more so than any
premeditation?
And it wasn’t the only time we got lucky. Graphene, which is a
monolayer of carbon atoms, is really hard to see—you can only see it
on a very special substrate. We didn’t know it at the time, but,
coincidentally, we had exactly that substrate and it was what we used,
purely by luck. I still don’t understand how that worked out, but the
substrate we had was exactly the one required. This was a huge
coincidence—just unbelievable. It was only a few months later that we
understood how lucky we had been. If not for that, I'm sure we would be
there anyway, but a bit later.
Were you literally using Scotch tape, or is that
just what you like to call it?
Yes, literally Scotch tape, at least initially. We later switched to a
Japanese tape—Nitto tape—which is used in the semiconductor
industry. I don’t know why we use Nitto tape; probably because the
whole process is so simple and cheap we wanted to fancy it up a little and
use this blue tape instead. Many people, though, are still using Scotch
tape and it works equally well.
What, in your view, are the most significant papers
for the field?
There are quite a few significant papers by now. Still, the very first ones
were the 2004 Science paper (Novoselov KS, et al.,
"Electric field effect in thin carbon films," 306[5696]: 666-9, 22 October
2004), and the Nature paper in 2005 (Novoselov KS, et
al., "Two-dimensional gas of massless Dirac fermions in graphene,"
438[7065]: 197-200, 10 November 2005). The paper by Philip Kim's group
published back-to-back with our Nature paper is also key to the
field. The Science paper started the field, demonstrating a method
for obtaining high-quality graphene. The Nature papers developed
the idea, demonstrating that the quasi-particles in this material have very
weird properties—they’re massless, for instance—and it
showed that the quality of the samples obtained is very high, so the
quantum Hall effect could be readily observed.
The Nature paper is the more highly cited
of the two, even though it was a follow-up publication. Why do you
think that is?
The interesting thing is that the first paper, the one in Science,
was originally submitted to Nature and, of course, it was
rejected, because…well, I don’t know why. The referee told us
it was interesting, but we should measure this, that, and the other thing
in addition, and then maybe they’d consider it for publication.
It’s now three years later and all those requirements made originally
by the Nature referee are still not measured. Nonetheless, we
improved our paper a bit and then published it half a year later in
Science.
As for citations, I think it’s now within five or ten percent of the
second paper, which was published in Nature. But the word
"graphene" isn’t in the title of the original. So people probably
overlook it a little bit. And it doesn’t have all that fancy stuff
that’s in the Nature paper, all the fancy words in the
title, like Dirac fermions in graphene. That sounds a lot more exciting. It
talks about the quantum Hall effect. It speaks to all possible communities
at once. The material scientists like graphene. The theorists like the
Dirac fermions, then there’s quantum Hall people, who also cite it.
It’s really, really interdisciplinary.
The first paper, the Science paper, really lays out the
background—how to prepare the films; it proves it exists, but
it’s not as all-around appealing. It’s quite easy to overlook.
And it’s not really the new material that makes this
exciting—it’s what you can do with this material, and
that’s all in the Nature paper. For us it was quite exciting
that you can get this field effect and have an ambipolar transistor effect.
You start with something very simple—a piece of graphite—and
you can get a working field-effect transistor by this very simple
technique. Nobody was working with this before.
To attract people to a new field of research, to make them change the
direction of their research, you have to show them really something that is
10 times more exciting than what they’re doing now. If it’s
only twice as exciting, nobody is going to change. And, of course, seeing a
phenomenon like that in a system as simple as this is really 10 times more
exciting than anyone else. That’s also probably why this 2005
Nature is more appealing.
What were the greatest challenges in performing and
presenting your work?
"…there are so many
interesting features to study with graphene
and we’re trying to work on them
all."
That there was no related work at that time at all. We had to develop all
the techniques from scratch, and we had to do so having no background of
any kind working with carbon. So we had to dig out an enormous amount of
literature trying to understand what’s going on. Also, as I said,
it’s multidisciplinary work. We knew we’d have people from
carbon, quantum Hall, and mesoscopics communities interested. So we had to
make the paper understandable and interesting to all of them.
What are you focusing on now in your
research?
Well, we’ve really diversified our research quite dramatically.
It’s all graphene, but there are so many interesting features to
study with graphene and we’re trying to work on them all. I hate the
fact that we don’t have time anymore to do Friday evening experiments
now, except those with graphene. We do some crazy stuff with graphene, but
nothing else. So we’re now working on quantum dots on graphene.
That’s one of the directions were going, and that’s for future
transistor applications. Even a few months ago, I was pessimistic about
that, but now I’m really starting to believe it might be used for
applications in the future.
Another area we’re working on is chemical derivatives of graphene.
One possibility is to look at graphene as a two-dimensional crystal.
Another is to look at it as a huge organic molecule that can be chemically
modified. By doing that, we can fine-tune its electronic properties by
altering the chemical bonds and chemical environment. We are working a lot
on that at the moment.
Another thing we’re doing, which is very down to earth, is very much
about applications. Graphene can be used not only for transistors but also
for other applications like transparent conductive coating—like the
display on your computer screen. The layer that is on your computer screen
is indium oxide; graphene can replace it quite happily and there are many
other such places, like solar cells, touch screen displays, etc. We are
developing this direction as well.
The funny thing is, with this transistor application, you have to produce a
few wafer-scale mono-crystals of graphene. Until a few months ago, I was
skeptical we could do this. Now I’m more positive. The liquid crystal
displays, though, don’t need mono-crystals of graphene; several
crystals interconnected with each other works equally well. We already have
the technology to produce those devices. In this respect, it’s ready
for applications now.
How would you describe the current state of affairs
in your field and its prospect for the future?
The field is developing extremely fast. Considering that the field is only
four years old, we’ve made enormous progress. Virtually every month,
it seems, someone comes up with an entirely new observation and so a
completely new area of research on graphene. There’s also
ever-increasing interest from industry, which helps to develop the field
even further. Now it’s clear that graphene is a very promising
material for practical applications.
If you performed your research again, or published
your paper again, what, if anything, would you do differently and
why?
You have to realize that we were working on graphene for at least a year,
probably a year and a half, before we published our first paper. So, yes,
if we could go back and do it again, we’d do a lot of things
differently; we’d know enough to cut the sharp corners and avoid the
dead ends. But that’s just hindsight. At the time, we needed to
accumulate a critical mass of knowledge and experience and the only way to
do that was trial and error. I don’t think that stage can ever be
eliminated in scientific research.
What would you like to convey to the general public
about your work?
That science should be fun, and you don’t always need to do expensive
multi-million dollar experiments to be on the cutting edge of
research.
Dr. Kostya Novoselov
School of Physics & Astronomy
University of Manchester
Manchester, UK
Novoselov KS, et al., "Two-dimensional gas of
massless Dirac fermions in graphene," Nature
438(7065): 197-200, 10 November 2005. Source:
Essential Science Indicators from
Thomson
Reuters.