Layered printed transistors could be step towards cheap, novel, electronic devices
Researchers based at Trinity College Dublin have printed transistors composed entirely of layered materials. This offers the promise of cheap electronics devices, with possible applications in interactive smart food, banknote security and e-passports.
Led by Professor Jonathan Coleman, the team used standard printing techniques to create transistors from graphene flakes and other layered materials which were just nanometres in thickness.
This technique allowed the researchers to precisely combine materials with different electronic properties. The conducting graphene functioned as electrodes, which semiconducting tungsten diselenide formed the channel and insulating boron nitride acted as the insulator.
Their all-printed, all-layered material transistor was fully functional.
The research was conducted as part of the Graphene Flagship; the EU’s biggest research initiative. The Graphene Flagship is a €1bn project to explore and exploit the properties of graphene. The team have reported their findings in Science.
Printed electronics are created by depositing electronic or optical inks onto a surface. Coleman’s team used inks created using a method he developed himself: the liquid exfoliation method.
Everyday printed equipment – such as inkjet or screen printing devices – can be used for printing electronics, allowing for the creation of low-cost, low-performance electronics, such as animated posters or light-up clothing.
“In the future, printed devices will be incorporated into even the most mundane objects such as labels, posters and packaging,” said Professor Coleman.
“Printed electronic circuitry will allow consumer products to gather, process, display and transmit information: for example, milk cartons will send messages to your phone warning that the milk is about to go out-of-date.
“We believe that layered materials can compete with the materials currently used for printed electronics.”
While this new thin-film transistor cannot compare to the performance of advanced transistors currently available, the researchers believe that there is potential to improve the performance of their transistor beyond the best on the market.