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.
Similar to carbon, silicon forms two dimensional networks that are only one atomic layer thick. Like graphene, for whose discovery Andre Geim and Konstantin Novoselov received the Nobel Prize in 2010, these layers possess extraordinary optoelectrical properties. Silicon nanosheets might thus find application in nanoelectronics, for example in flexible displays, field-effect transistors and photodetectors. With its ability to store lithium ions, it is also under consideration as an anode material in rechargeable lithium batteries.
Extruded spiral made of polymer-coated silicon-nanosheets glowing in UV light
Photo: Tobias Helbich / TUM
“Silicon nanosheets are particularly interesting because today’s information technology builds on silicon and, unlike with graphene, the basic material does not need to be exchanged,” explains Tobias Helbich from the WACKER Chair for Macromolecular Chemistry at TUM. “However, the nanosheets themselves are very delicate and quickly disintegrate when exposed to UV light, which has significantly limited their application thus far.”
Polymer and nanosheets – the best of both worlds in one
Now Helbich, in collaboration with Professor Bernhard Rieger, Chair of Macromolecular Chemistry, has for the first time successfully embedded the silicon nanosheets into a polymer, protecting them from decay. At the same time, the nanosheets are protected against oxidation. This is the first nanocomposite based on silicon nanosheets.
“What makes our nanocomposite special is that it combines the positive properties of both of its components,” explains Tobias Helbich. “The polymer matrix absorbs light in the UV domain, stabilizes the nanosheets and gives the material the properties of the polymer, while at the same time maintaining the remarkable optoelectronic properties of the nanosheets.”
Long-term goal of nanoelectronics – In leaps and bounds to industrial application
Its flexibility and durability against external influences also makes the newly developed material amenable to standard polymer technology for industrial processing. This puts actual applications within an arm’s reach.
The composites are particularly well suited for application in the up and coming field of nanoelectronics. Here, “classical” electronic components like circuits and transistors are implemented on scales of less than 100 nanometers. This allows whole new technologies to be realized – for faster computer processors, for example.
The first successful application of the nanocomposite constructed by Helbich was only recently presented in the context of the ATUMS Graduate Program (Alberta / TUM International Graduate School for Functional Hybrid Materials): Alina Lyuleeva and Prof. Paolo Lugli from the Institute of Nanoelectronics at TU Munich, in collaboration with Helbich and Rieger, succeeded in building a photodetector based on these silicon nanosheets.
To this end, they mounted the polymer embedded silicon nanosheets onto a silicon dioxide surface coated with gold contacts. Because of its Lilliputian dimensions, this kind of nanoelectronic detector saves a lot of both space and energy.
The research is part of the ATUMS Graduate Program (Alberta / TUM International Graduate School for Functional Hybrid Materials (ATUMS; IRTG 2022)) in which German and Canadian scientists in the fields of chemistry, electrical engineering and physics collaborate closely. Their goal is not only to create novel functions based on nanoparticles and polymer materials, but, at the same time, to develop first applications. The work is funded by the German Research Council (DFG) and the Natural Science and Engineering Research Council of Canada (NSERC).
Helbich, T., Lyuleeva, A., Ludwig, T., Scherf, L. M., Fässler, T. F., Lugli, P., & Rieger, B.
One‐Step Synthesis of Photoluminescent Covalent Polymeric Nanocomposites from 2D Silicon Nanosheets
Advanced Functional Materials, 26(37), 6711-6718 – DOI: 10.1002/adfm.201602137
Lyuleeva, A., Helbich, T., Rieger, B., Lugli, P.
Polymer-Silicon Nanosheet Composites: Bridging the Way to Optoelectronic Applications
Journal of Physics D: Applied Physics, 2017, Vol 50, 135106 – DOI: 10.1088/1361-6463/aa5005
Prof. Dr. Bernhard Rieger
Wacker-Chair of Macromolecular Chemistry
Technical University of Munich
Lichtenbergstraße 4, 85747 Garching
Tel.: +49 89 289 13571 – E-Mail: firstname.lastname@example.org
Web: http://www.makro.ch.tum.de/index.php?id=1280&L=1 – http://www.makro.ch.tum.de/index.php?id=2598
https://www.tum.de/en/about-tum/news/press-releases/detail/article/33796/ Link to the press release
Dr. Ulrich Marsch | Technische Universität München
The stacked colour sensor
16.11.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Counterfeits and product piracy can be prevented by security features, such as printed 3-D microstructures
16.11.2017 | Karlsruher Institut für Technologie (KIT)
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses