Research turning coloured pigments into electronics

Researchers have detailed how a family of organic pigments are set to drive the future of electronic devices. This includes wearable technology made from bendable and stretchable transistors and biodegradable devices to solve the electronic waste issue.

QUT Associate Professor Prashant Sonar leads a team of researchers who, in an article in the journal Advanced Materials (, discuss the latest developments around the world using organic pigments called diketopyrrolopyrrole (DPP).

DPPs are carbon-based organic materials that are used for their colour as dyes and for their charge transporting and optoelectronic properties. Optoelectronics involves devices that convert light into electrical signals and electrical energy into light.

“The next business coming is stretchable,” Professor Sonar said.

One of the advantages of the using pigments with electronics is that they can be printed on a range of materials. This means flexible materials can become solar cells, transistors and sensors and used in many ways ranging from medical devices designed to be inserted into the body to technology products designed to break down rather than end up as more e-waste.

“With the fast growth of high-mobility materials, they are increasingly considered for use in stretchable electronic devices that can provide unique mechanical properties including being able to be bent, twisted, stretched, and wrapped over irregular or moving objects,” Professor Sonar said.

“All these properties are attractive for biomedical instruments, wearable electronics, bioinspired devices, and artificial skin for robotics and prosthetics.

“With these types of devices, we’re not looking at the scale of 20 years or 30 years, we are looking at the scale of three, four or five years and for all these applications, low-cost printable organic semiconductors is the bottleneck.”

Professor Sonar’s research group last year discovered a new material by combining DPP Pigment Red 254 – the colour nicknamed Ferrari Red because of its use by the iconic car maker – and naphthalene, well known as an ingredient in moth repellents.

The new DPP derivative, naphthalene flanked DPP or DPPN, has potential uses in organic transistors and flexible solar cells.

Professor Sonar also recently developed semiconductor materials using another class of an orange dye called anthanthrone (ANT) which could be used in the future for ‘perovskite’ flexible solar cells built into curtains, sail shades or even clothing.

Along with flexibility, an advantage DPP pigments have in use in organic electronic devices is that they are lower cost, lighter weight and are produced without the need to mine valuable resources.

Professor Sonar is a Chief Investigator with the QUT Centre for Materials Science, which has the mission to design, discover, and develop advanced functional materials to solve key technological challenges across four research themes – soft matter; hard matter; computation, prediction and modelling; and analytical methods.

Professor Sonar has published more than 60 papers on DPP pigments and their uses and has licenced two patents for DPP substances to a US-based conglomerate.

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