Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Organic electronics with an edge


Two-dimensional organic lattices are easier and safer to work with than inorganic materials for spintronic and quantum computing applications.

Using sophisticated theoretical tools, Agency for Science, Technology and Research (A*STAR) researchers, in Singapore, have identified a way to construct topological insulators — a new class of spin-active materials — out of planar organic-based complexes rather than toxic inorganic crystals [1].

A*STAR researchers have used a combination of quantum calculations and band-structure simulations to design topological insulators based on two-dimensional organic-based nanosheets.

© agsandrew/iStock/Thinkstock

The unique crystal structure of topological insulators makes them insulating everywhere, except around their edges. Because the conductivity of these materials is localized into quantized surface states, the current passing through topological insulators acquires special characteristics. For example, it can polarize electron spins into a single orientation — a phenomenon that researchers are exploiting to produce ‘spin–orbit couplings’ that generate magnetic fields for spintronics without the need for external magnets.

Many topological insulators are made by repeatedly exfoliating inorganic minerals, such as bismuth tellurides or bismuth selenides, with sticky tape until flat, two-dimensional (2D) sheets appear. “This gives superior properties compared to bulk crystals, but mechanical exfoliation has poor reproducibility,” explains Shuo-Wang Yang from the A*STAR Institute of High Performance Computing. “We proposed to investigate topological insulators based on organic coordination complexes, because these structures are more suitable for traditional wet chemical synthesis than inorganic materials.”

Coordination complexes are compounds in which organic molecules known as ligands bind symmetrically around a central metal atom. Yang and his team identified novel ‘shape-persistent’ organic ligand complexes as good candidates for their method. These compounds feature ligands made from small, rigid aromatic rings. By using transition metals to link these organic building blocks into larger rings known as ‘macrocycles’, researchers can construct extended 2D lattices that feature high charge carrier mobility.

Pinpointing 2D organic lattices with desirable topological insulator properties is difficult when relying only on experiments. To refine this search, Yang and colleagues used a combination of quantum calculations and band structure simulations to screen the electronic activity of various shape-persistent organic complexes. The team looked for two key factors in their simulations: ligands that can delocalize electrons in a 2D plane similar to graphene and strong spin–orbit coupling between central transition metal nodes and ligands.

The researchers’ new family of potential organic topological insulators has a 2D honeycomb macrocycles containing tri-phenyl rings, palladium or platinum metals, and amino linking groups. With promising quantum features and high theoretical stability, these complexes may serve as topological insulators in real world applications.

“These materials are easy to fabricate, and cheaper than their inorganic counterparts,” says Yang. “They are also suitable for assembling directly onto semiconductor surfaces, which makes nanoelectronic applications more feasible.”

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing and the Institute of Materials Research and Engineering. For more information about the team’s research, please visit the Materials Science & Engineering webpage.


[1] Zhou, Q., Wang, J., Chwee, T. S., Wu, G., Wang, X. et al.Topological insulators based on 2D shape-persistent organic ligand complexes. Nanoscale 7, 727–735 (2015).

Associated links
Original article from A*STAR Research

A*STAR Research | Research SEA
Further information:

More articles from Machine Engineering:

nachricht Process-Integrated Inspection for Ultrasound-Supported Friction Stir Welding of Metal Hybrid-Joints
27.09.2016 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP

nachricht Lightweight robots in manual assembly
13.09.2016 | Fraunhofer-Institut für Arbeitswirtschaft und Organisation IAO

All articles from Machine Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>