Researchers fabricate printed transistors using Graphene flakes

Graphene Flagship researchers from AMBER at Trinity College, Dublin, successfully created film transistors consisting entirely of layered materials.

The team's findings, published in the journal 'Science,' revealed the possibility to print a range of electronic devices from solar cells to LEDs, with applications from interactive smart food and drug labels to next-generation banknote security and e-passports.

Led by Professor Jonathan Coleman from AMBER, in collaboration with Professor Georg Duesberg (AMBER) and Professor Laurens Siebbeles (TU Delft, Netherlands), the team used standard printing techniques to combine graphene flakes as the electrodes with other layered materials, tungsten diselenide and boron nitride, as the channel and separator to form all-printed, all-layered materials, working transistor.

The flakes are a few nanometers thick, but hundreds of nanometers wide. Critically, it is the ability of flakes, made from different layered materials to have electronic properties that can be conducting (in the case of graphene), insulating (boron nitride) or semiconducting (tungsten diselenide) that enable them to create the building blocks of electronics.

While the performance of these printed layered devices cannot yet compare with advanced transistors, the team believes there is a wide scope to improve the performance of their printed TFTs beyond the current state-of-the-art.

"In the future, printed devices will be incorporated into even the most mundane objects such as labels, posters and packaging. Printed electronic circuitry will allow consumer products to gather, process, display and transmit information. We believe that layered materials can compete with the materials currently used for printed electronics," said researcher Coleman.

All of the layered materials were printed from inks created using the liquid exfoliation method previously developed by Professor Coleman and already licensed.

Using liquid processing techniques to create the layered materials inks is especially advantageous in that it yields large quantities of high quality layered materials which helps to enable the potential to print circuitry at low cost.