Irish researchers print transistors from 2D nanomaterials

Standard printing techniques combine graphene sheets with WSe₂ and BN to make working transistors

Jonathan Coleman and team have fabricated printed transistors consisting entirely of 2Dvnanomaterials for the first time.

Researchers in AMBER, the Science Foundation Ireland-funded materials science research centre hosted in Trinity College Dublin, have fabricated printed transistors consisting entirely of 2D nanomaterials for the first time.

Led by Jonathan Coleman, in collaboration with the groups of Georg Duesberg (AMBER) and Laurens Siebbeles (TU Delft, Netherlands), the team used standard printing techniques to combine graphene nanosheets as the electrodes with two other nanomaterials, WSe₂ and BN as the channel and separator to form an all-printed, all-nanosheet, working transistor.

According to the researchers, this breakthrough could unlock the potential for applications such as food packaging that displays a digital countdown to warn you of spoiling, wine labels that alert you when your white wine is at its optimum temperature, or even a window pane that shows the day’s forecast. The AMBER team’s findings have been published in a paper ‘All-printed thin-film transistors from networks of liquid-exfoliated nano sheets’ in the journal Science.

Coleman, an investigator in AMBER and Trinity’s School of Physics, said: “In the future, printed devices will be incorporated into even the most mundane objects such as labels, posters and packaging. Printed electronic circuitry (constructed from the devices we have created) will allow consumer products to gather, process, display and transmit information: for example, milk cartons could send messages to your phone warning that the milk is about to go out-of-date.

“This publication is important because it shows that conducting, semiconducting and insulating 2D nanomaterials can be combined together in complex devices. We felt that it was critically important to focus on printing transistors as they are the electric switches at the heart of modern computing. We believe this work opens the way to print a whole host of devices solely from 2D nano sheets.”

Coleman has licensed his scalable method of producing 2D nanomaterials to Samsung and Thomas Swan.

Printable electronics have developed over the last thirty years based mainly on printable carbon-based molecules. While these molecules can easily be turned into printable inks, such materials are somewhat unstable and have well-known performance limitations.

There have been many attempts to surpass these obstacles using alternative materials, such as carbon nanotubes or inorganic nanoparticles, but these materials have also shown limitations in either performance or in manufacturability. While the performance of printed 2D devices cannot yet compare with advanced transistors, the team believe there is a wide scope to improve performance beyond the current state-of-the-art for printed transistors.