Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Redesigned Material Could Lead to Lighter, Faster Electronics

12.04.2013
Thin Layer of Germanium May Replace Silicon in Semiconductors

The same material that formed the first primitive transistors more than 60 years ago can be modified in a new way to advance future electronics, according to a new study.

Chemists at The Ohio State University have developed the technology for making a one-atom-thick sheet of germanium, and found that it conducts electrons more than ten times faster than silicon and five times faster than conventional germanium.

The material’s structure is closely related to that of graphene—a much-touted two-dimensional material comprised of single layers of carbon atoms. As such, graphene shows unique properties compared to its more common multilayered counterpart, graphite. Graphene has yet to be used commercially, but experts have suggested that it could one day form faster computer chips, and maybe even function as a superconductor, so many labs are working to develop it.

Joshua Goldberger, assistant professor of chemistry at Ohio State, decided to take a different direction and focus on more traditional materials.

“Most people think of graphene as the electronic material of the future,” Goldberger said. “But silicon and germanium are still the materials of the present. Sixty years’ worth of brainpower has gone into developing techniques to make chips out of them. So we’ve been searching for unique forms of silicon and germanium with advantageous properties, to get the benefits of a new material but with less cost and using existing technology.”

In a paper published online in the journal ACS Nano, he and his colleagues describe how they were able to create a stable, single layer of germanium atoms. In this form, the crystalline material is called germanane.

Researchers have tried to create germanane before. This is the first time anyone has succeeded at growing sufficient quantities of it to measure the material’s properties in detail, and demonstrate that it is stable when exposed to air and water.

In nature, germanium tends to form multilayered crystals in which each atomic layer is bonded together; the single-atom layer is normally unstable. To get around this problem, Goldberger’s team created multi-layered germanium crystals with calcium atoms wedged between the layers. Then they dissolved away the calcium with water, and plugged the empty chemical bonds that were left behind with hydrogen. The result: they were able to peel off individual layers of germanane.

Studded with hydrogen atoms, germanane is even more chemically stable than traditional silicon. It won’t oxidize in air and water, as silicon does. That makes germanane easy to work with using conventional chip manufacturing techniques.

The primary thing that makes germanane desirable for optoelectronics is that it has what scientists call a “direct band gap,” meaning that light is easily absorbed or emitted. Materials such as conventional silicon and germanium have indirect band gaps, meaning that it is much more difficult for the material to absorb or emit light.

“When you try to use a material with an indirect band gap on a solar cell, you have to make it pretty thick if you want enough energy to pass through it to be useful. A material with a direct band gap can do the same job with a piece of material 100 times thinner,” Goldberger said.

The first-ever transistors were crafted from germanium in the late 1940s, and they were about the size of a thumbnail. Though transistors have grown microscopic since then—with millions of them packed into every computer chip—germanium still holds potential to advance electronics, the study showed.

According to the researchers’ calculations, electrons can move through germanane ten times faster through silicon, and five times faster than through conventional germanium. The speed measurement is called electron mobility.

With its high mobility, germanane could thus carry the increased load in future high-powered computer chips.

“Mobility is important, because faster computer chips can only be made with faster mobility materials,” Golberger said. “When you shrink transistors down to small scales, you need to use higher mobility materials or the transistors will just not work,” Goldberger explained.

Next, the team is going to explore how to tune the properties of germanane by changing the configuration of the atoms in the single layer.

Lead author of the paper was Ohio State undergraduate chemistry student Elizabeth Bianco, who recently won the first place award for this research at the nationwide nanotechnology competition NDConnect, hosted by the University of Notre Dame. Other co-authors included Sheneve Butler and Shishi Jiang of the Department of Chemistry and Biochemistry, and Oscar Restrepo and Wolfgang Windl of the Department of Materials Science and Engineering.

The research was supported in part by an allocation of computing time from the Ohio Supercomputing Center, with instrumentation provided by the Analytical Surface Facility in the Department of Chemistry and Biochemistry and the Ohio State University Undergraduate Instrumental Analysis Program. Funding was provided by the National Science Foundation, the Army Research Office, the Center for Emergent Materials at Ohio State, and the university’s Materials Research Seed Grant Program.

Contact: Joshua Goldberger, (614) 247-7438; Goldberger@chemistry.ohio-state.edu
Written by Pam Frost Gorder, (614) 292-9475; Gorder.1@osu.edu
Images of germanium in its natural state and a germanane sheet are available from Pam Frost Gorder.

Pam Frost Gorder | Newswise
Further information:
http://www.osu.edu

More articles from Materials Sciences:

nachricht Nanomaterial makes laser light more applicable
28.03.2017 | Christian-Albrechts-Universität zu Kiel

nachricht New value added to the ICSD (Inorganic Crystal Structure Database)
27.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>