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
Using fine-tuning for record-breaking performance
14.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
Materials scientist creates fabric alternative to batteries for wearable devices
12.11.2018 | University of Massachusetts at Amherst
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
14.11.2018 | Life Sciences
14.11.2018 | Life Sciences
14.11.2018 | Earth Sciences