Flexible electronics hold promise
New research into organic semiconductors advances field
Plastic-based flexible electronics, produced in large volume using roll-to-roll processing, inkjet printing or spray deposition, is the “electronics everywhere” trend of the future, says Oana Jurchescu, assistant professor of physics at Wake Forest University. And the key to success in this market will be the low-cost production of large molecular structures with excellent electronic performance.
Jurchescu, her two graduate students Katelyn Goetz and Jeremy Ward, and interdisciplinary collaborators from Stanford, Imperial College (London), University of Kentucky and Appalachian State have developed just such an organic semiconductor.
In the current consumer market, the word “electronic” is generally associated with the word “expensive.” This is largely because products such as televisions, computers and cell phones are based on silicon, which is costly to produce. Organic electronics, however, build on carbon-based (plastic) materials, which offer not only ease of manufacturing and low cost, but also lightweight, and mechanical flexibility, says Jurchescu. For this reason, the technology may eventually be used to make artificial skin, smart bandages, flexible displays, smart windshields, wearable electronics and electronic wall papers that change patterns with a flip of the switch, everyday realities.
The team recently published their manuscript in Advanced Materials, one of the most prestigious journals in the ﬁeld of materials research.
The work presents, for the first time, the development of an extremely large molecule that is both stable and possesses excellent electrical properties, while keeping the cost low. Prior researchers predicted that larger carbon frameworks would have properties superior to their smaller counterparts, but until now there has not been an effective route to make these larger frameworks stable and soluble enough for study.
“To accelerate the use of these technologies, we need to improve our understanding of how they work,” Jurchescu says. “The devices we study (field-effect transistors) are the fundamental building blocks in all modern-based electronics. Our findings shed light on the effect of the structure of the molecules on their electrical performance and pave the way towards a design of improved materials for high-performance, low-cost, plastic-based electronics.”
The team studied new organic semiconductor materials amenable to transistor applications and explored their structure-property relationships. Organic semiconductors are a type of plastic material characterized by a specific structure that makes them conductive. In modern electronics, a circuit uses transistors to control the current between various regions of the circuit.
The results of the published research may lead to significant technological improvements as the performance of the transistor determines the switching speed, contrast details and other key properties of the display.