Physics professor Oana Jurchescu and grad students Jeremy Ward and Katelyn Goetz (left to right). |
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.
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.
