Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rice U. study sheds light on -- and through -- 2D materials

25.09.2018

High-performance computing helps to survey optical qualities of atom-thick materials for optoelectronics

The ability of metallic or semiconducting materials to absorb, reflect and act upon light is of primary importance to scientists developing optoelectronics - electronic devices that interact with light to perform tasks. Rice University scientists have now produced a method to determine the properties of atom-thin materials that promise to refine the modulation and manipulation of light.


Rice University researchers modeled two-dimensional materials to quantify how they react to light. They calculated how the atom-thick materials in single or stacked layers would transmit, absorb and reflect light. The graphs above measure the maximum absorbance of several of the 55 materials tested.

Credit: Yakobson Research Group/Rice University

Two-dimensional materials have been a hot research topic since graphene, a flat lattice of carbon atoms, was identified in 2001. Since then, scientists have raced to develop, either in theory or in the lab, novel 2D materials with a range of optical, electronic and physical properties.

Until now, they have lacked a comprehensive guide to the optical properties those materials offer as ultrathin reflectors, transmitters or absorbers.

The Rice lab of materials theorist Boris Yakobson took up the challenge. Yakobson and his co-authors, graduate student and lead author Sunny Gupta, postdoctoral researcher Sharmila Shirodkar and research scientist Alex Kutana, used state-of-the-art theoretical methods to compute the maximum optical properties of 55 2D materials.

"The important thing now that we understand the protocol is that we can use it to analyze any 2D material," Gupta said. "This is a big computational effort, but now it's possible to evaluate any material at a deeper quantitative level."

Their work, which appears this month in the American Chemical Society journal ACS Nano, details the monolayers' transmittance, absorbance and reflectance, properties they collectively dubbed TAR. At the nanoscale, light can interact with materials in unique ways, prompting electron-photon interactions or triggering plasmons that absorb light at one frequency and emit it in another.

Manipulating 2D materials lets researchers design ever smaller devices like sensors or light-driven circuits. But first it helps to know how sensitive a material is to a particular wavelength of light, from infrared to visible colors to ultraviolet.

"Generally, the common wisdom is that 2D materials are so thin that they should appear to be essentially transparent, with negligible reflection and absorption," Yakobson said. "Surprisingly, we found that each material has an expressive optical signature, with a large portion of light of a particular color (wavelength) being absorbed or reflected."

The co-authors anticipate photodetecting and modulating devices and polarizing filters are possible applications for 2D materials that have directionally dependent optical properties. "Multilayer coatings could provide good protection from radiation or light, like from lasers," Shirodkar said. "In the latter case, heterostructured (multilayered) films -- coatings of complementary materials -- may be needed. Greater intensities of light could produce nonlinear effects, and accounting for those will certainly require further research."

The researchers modeled 2D stacks as well as single layers. "Stacks can broaden the spectral range or bring about new functionality, like polarizers," Kutana said. "We can think about using stacked heterostructure patterns to store information or even for cryptography."

Among their results, the researchers verified that stacks of graphene and borophene are highly reflective of mid-infrared light. Their most striking discovery was that a material made of more than 100 single-atom layers of boron -- which would still be only about 40 nanometers thick -- would reflect more than 99 percent of light from the infrared to ultraviolet, outperforming doped graphene and bulk silver.

There's a side benefit that fits with Yakobson's artistic sensibility as well. "Now that we know the optical properties of all these materials - the colors they reflect and transmit when hit with light - we can think about making Tiffany-style stained-glass windows on the nanoscale," he said. "That would be fantastic!"

###

Editor's note: A link to a high-resolution image for download appears at the end of this release.

David Ruth 713-348-6327?david@rice.edu

Mike Williams 713-348-6728?mikewilliams@rice.edu

The work was supported by the U.S. Army Research Office and the Robert Welch Foundation. Computing resources were provided by the National Science Foundation-supported DAVinCI cluster at Rice, administered by the Center for Research Computing and procured in partnership with Rice's Ken Kennedy Institute for Information Technology, the Department of Defense High Performance Computing Modernization Program and the Department of Energy Office of Science's National Energy Research Scientific Computing Center.

Read the abstract at https://pubs.acs.org/doi/10.1021/acsnano.8b03754.

This news release can be found online at http://news.rice.edu/2018/09/24/rice-u-study-sheds-light-on-and-through-2d-materials/

Follow Rice News and Media Relations via Twitter @RiceUNews.

Related materials:

Yakobson Research Group: https://biygroup.blogs.rice.edu

Rice Department of Materials Science and NanoEngineering: https://engineering.rice.edu

George R. Brown School of Engineering: https://msne.rice.edu

Image for download:

http://news.rice.edu/files/2018/09/0924_2D-1a-WEB-231u7gy.jpeg

Rice University researchers modeled two-dimensional materials to quantify how they react to light. They calculated how the atom-thick materials in single or stacked layers would transmit, absorb and reflect light. The graphs above measure the maximum absorbance of several of the 55 materials tested. (Credit: Yakobson Research Group/Rice University)

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,970 undergraduates and 2,934 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 2 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl.com/RiceUniversityoverview.

Media Contact

Mike Williams
mikewilliams@rice.edu
713-348-6728

 @RiceUNews

http://news.rice.edu 

Mike Williams | EurekAlert!
Further information:
http://news.rice.edu/2018/09/24/rice-u-study-sheds-light-on-and-through-2d-materials/
http://dx.doi.org/10.1021/acsnano.8b03754

More articles from Materials Sciences:

nachricht Understanding high efficiency of deep ultraviolet LEDs
22.02.2019 | Tohoku University

nachricht Large-scale window material developed for PM2.5 capture and light tuning
18.02.2019 | University of Science and Technology of China

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>