Molecules used to make optoelectronic devices can be engineered to have specific properties, making the production of high-performance optoelectronic devices more efficient, according to a paper in Science and Technology of Advanced Materials.
The molecules used to make optoelectronic devices can be engineered to balance the chemical interactions within them and optimise their properties for specific applications, according to a review paper published in the journal Science and Technology of Advanced Materials.
This paper, by researchers at the National Institute for Materials Science (NIMS) in Japan, proposes engineering strategies that could advance the manufacture of a range of devices.
Optoelectronic devices convert electricity into light, or light into electricity, and are integral to an increasing number of devices. For example, many television and mobile device displays are made with optoelectronic organic light-emitting diodes (OLEDs). Optoelectronics are also central to solar-powered devices, fibre optic communication and some electronic chips.
Many materials that are used to make optoelectronics consist of “π-conjugated” molecules that feature a complex form of chemical bonding in which many electrons are shared between many atoms. This bonding confers electronic and optical properties that are ideal for optoelectronics, but also leads to limitations. For example, at room temperature, most of these materials are solid and, therefore, unsuitable for flexible devices. What’s more, π-conjugated molecules tend to be insoluble in solvents and difficult to work with in printing technology.
However, these properties can be changed by attaching alkyl chains to the π-conjugated molecules (alkyl chains have a backbone of carbon atoms, but can vary in length and branching structure). Scientists lack a complete understanding of how alkyl chains affect the properties of π-conjugated molecules, but Fengniu Lu and Takashi Nakanishi of NIMS have reviewed a range of studies to determine the fundamental rules of the process.
(Since 2005, Dr. Nakanishi has himself invented a way to control the self assembly of linear alkyl chains, such as alkylated-fullerenes, to π-conjugated molecules. In addition, he recently developed an intriguing technique to create luminescent, room temperature “liquid” π-conjugated molecules by wrapping the π-moiety up with several branched alkyl chains.)
To assess the effects of attached alkyl chains, the NIMS team collated research that studied the properties of π-conjugated molecules modified with specific alkyl chains. Some studies demonstrated that different types of alkyl chains, solvent polarity, temperature and chain–substrate interactions led to the assembly of π-conjugated molecules into various two- and three-dimensional structures.
Other studies showed that alkyl chains with certain structures allowed the formation of “thermotropic” liquid crystalline materials — which have properties between those of hard solids and soft liquids — as well as the formation of materials that were “isotropic” liquids at room temperature and from which photoconducting liquid crystals or gels could be formed. The authors describe this strategy as “alkyl-π engineering” in their review article.
The researchers conclude that changes in the properties of alkylated-π molecules depend upon the precise balance of the interactions among the π-conjugated units as well as static interactions (known as van der Waals forces) among the alkyl chains. Different alkyl chains affect the balance of these interactions, leading to different molecular structures and properties. This insight will allow researchers to deliberately engineer π-conjugated molecules to have specific properties, making the production of high-performance optoelectronic devices more efficient.
For further information contact:
Dr. Takashi Nakanishi
International Center for Materials Nanoarchitectonics (MANA),
National Institute for Materials Science (NIMS)
More information about the research paper:
Sci. Technol. Adv. Mater. Vol. 16 (2015) 014805
Alkyl-π engineering in state control toward versatile optoelectronic soft materials
Fengniu Lu and Takashi Nakanishi
Science and Technology of Advanced Materials (STAM) is the leading open access, international journal for outstanding research articles across all aspects of materials science. Our audience is the international materials community across the disciplines of materials science, physics, chemistry, biology as well as engineering.
The journal covers a broad spectrum of materials science research including functional materials, synthesis and processing, theoretical analyses, characterization and properties of materials. Emphasis is placed on the interdisciplinary nature of materials science and issues at the forefront of the field, such as energy and environmental issues, as well as medical and bioengineering applications
For more information about the journal Science and Technology of Advanced Materials, please contact
TITLE: Publishing Director
National Institute for Materials Science
Science and Technology of Advanced Materials
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