Nav: Home

World's widest graphene nanoribbon promises the next generation of miniaturized electronics

June 30, 2020

With literally the thickness of one carbon atom and electrical properties that can surpass those of standard semiconductor technologies, graphene nanoribbons promise a new generation of miniaturized electronic devices. The theory, however, remains far ahead of reality, with current graphene nanoribbons falling short of their potential. A new collaborative study seen in Communications Materials by a project of CREST, JST Japan including Nara Institute of Science and Technology (NAIST), Fujitsu Laboratories Ltd. and Fujitsu Ltd., and the University of Tokyo reports the first ever 17-carbon wide graphene nanoribbon and confirms it has the smallest bandgap seen to date among known graphene nanoribbons prepared by a bottom-up manner.

Large-scale integrated circuits (LSIs) that use silicon semiconductors are used in a wide range of electronic devices, anywhere from computers to smartphones. They are actually supporting our lives and almost everything else these days. However, although LSIs have improved device performance by reducing the size of the devices, LSI miniaturization is approaching its limit. At the same time, commercial demand continues to put pressure on companies to make higher performing smartphones at smaller sizes, while industry pressure is demanding large-scale manufacturing with smaller equipment.

Other methods and/or materials are definitely needed to solve these problems, says the group leader Dr. Shintaro Sato, Fujitsu Ltd.

"Silicon semiconductors are giving us better performance at smaller sizes. However, we are reaching the limit in how small we can make devices. Thus, we have high expectations for the performance of graphene nanoribbons, which have semi-conducting properties that are only one atom thick - a 2D material," he notes.

Graphene nanoribbons are honeycomb-like structures and, compared to graphene and carbon nanotubes, are the lesser known carbon-based semiconductor family member. Graphene nanoribbons exhibit unique electronic and magnetic properties that do not appear in two-dimensional graphene.

"Interestingly, the electronic and magnetic properties of graphene nanoribbons are widely tuned as a function of the width and edge structure." says Prof. Hiroko Yamada at NAIST.

Armchair-type graphene nanoribbons, which are promising type of nanoribbon for device application, display width-dependent band gap. They can be classified into three subfamilies (3p, 3p + 1, 3p + 2), their band gaps being inversely proportional to the width of those families. Basically, wider armchair-edge graphene nanoribbons belonging to the 3p + 2 subfamily have the smallest bandgaps among different graphene nanoribbons, having considerable potential to be exploited in GNR-based devices.

So far, 13-armchair graphene nanoribbons belonging to the 3p + 1 subfamily with a band gap of more than 1 eV have been reported, but Sato, Yamada and colleagues show the synthesis of a 17-graphene nanoribbon belonging to the 3p + 2 subfamily, which have even smaller bandgaps.

The graphene nanoribbon synthesis was based on the bottom-up approach, called "on-surface synthesis," and a dibromobenzene-based molecule was used as a precursor for on-surface graphene nanoribbon synthesis.

"There are many methods to synthesize graphene nanoribbons, but to produce atomically precise graphene nanoribbons, we decided to use the bottom-up approach. The important point is that the structure of the precursor can define the ultimate structure of graphene nanoribbons if we use the bottom-up approach," explains NAIST's Dr. Hironobu Hayashi, who also contributed to the study.

Scanning tunnel microscopy and spectroscopy by Dr. Junichi Yamaguchi at Fujitsu. Ltd. and non-contact atomic force microscopy by Dr. Akitoshi Shiotari and Prof. Yoshiaki Sugimoto at The University of Tokyo confirmed the atomic and electronic structure of the acquired 17-armchair graphene nanoribbons. Additionally, the experimentally obtained bandgap of 17-armchair graphene nanoribbons was found to be 0.6 eV, and this is the first demonstration of the synthesis of graphene nanoribbons having a band gap smaller than 1 eV in a controlled manner.

"We expect these 17-carbon wide graphene nanoribbons to pave the way for new GNR-based electronic devices," says Sato.
-end-
Resource

Title: Small bandgap features achieved in atomically precise 17-atom-wide armchair-edged graphene nanoribbons

Authors: Junichi Yamaguchi, Hironobu Hayashi, Hideyuki Jippo, Akitoshi Shiotari, Manabu Ohtomo, Mitsuhiro Sakakura, Nao Hieda, Naoki Aratani, Mari Ohfuchi, Yoshiaki Sugimoto, Hiroko Yamada & Shintaro Sato

Journal:Communications Materials

DOI: 10.1038/s43246-020-0039-9

Information about Prof. Yamada lab can be found at the following website:https://mswebs.naist.jp/LABs/env_photo_greenmat/en/index.html

Nara Institute of Science and Technology

Related Graphene Articles:

How to stack graphene up to four layers
IBS research team reports a novel method to grow multi-layered, single-crystalline graphene with a selected stacking order in a wafer scale.
Graphene-Adsorbate van der Waals bonding memory inspires 'smart' graphene sensors
Electric field modulation of the graphene-adsorbate interaction induces unique van der Waals (vdW) bonding which were previously assumed to be randomized by thermal energy after the electric field is turned off.
Graphene: It is all about the toppings
The way graphene interacts with other materials depends on how these materials are brought into contact with the graphene.
Discovery of graphene switch
Researchers at Japan Advanced Institute of Science and Technology (JAIST) successfully developed the special in-situ transmission electron microscope technique to measure the current-voltage curve of graphene nanoribbon (GNR) with observing the edge structure and found that the electrical conductance of narrow GNRs with a zigzag edge structure abruptly increased above the critical bias voltage, indicating that which they are expected to be applied to switching devices, which are the smallest in the world.
New 'brick' for nanotechnology: Graphene Nanomesh
Researchers at Japan advanced institute of science and technology (JAIST) successfully fabricated suspended graphene nanomesh (GNM) by using the focused helium ion beam technology.
Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.
Graphene Flagship publishes handbook of graphene manufacturing
The EU-funded research project Graphene Flagship has published a comprehensive guide explaining how to produce and process graphene and related materials (GRMs).
How to induce magnetism in graphene
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechani-cal, electronic and optical properties.
Graphene: The more you bend it, the softer it gets
New research by engineers at the University of Illinois combines atomic-scale experimentation with computer modeling to determine how much energy it takes to bend multilayer graphene -- a question that has eluded scientists since graphene was first isolated.
How do you know it's perfect graphene?
Scientists at the US Department of Energy's Ames Laboratory have discovered an indicator that reliably demonstrates a sample's high quality, and it was one that was hiding in plain sight for decades.
More Graphene News and Graphene Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

How to Win Friends and Influence Baboons
Baboon troops. We all know they're hierarchical. There's the big brutish alpha male who rules with a hairy iron fist, and then there's everybody else. Which is what Meg Crofoot thought too, before she used GPS collars to track the movements of a troop of baboons for a whole month. What she and her team learned from this data gave them a whole new understanding of baboon troop dynamics, and, moment to moment, who really has the power.  This episode was reported and produced by Annie McEwen. Support Radiolab by becoming a member today at Radiolab.org/donate.