Turkish researchers make ‘graphene paper’ as flexible display

By overlaying a graphene film over standard printer paper, researchers at Bilkent University in Ankara were able to create a rudimentary flexible electronic display. The display functions by running a current through the graphene.

The current causes the graphene layer’s way of absorbing light to change. In other words, it ensures that the graphene layer is black or semi-transparent through intercalation. The transition from opaque to semi-transparent took some time in the experiments, namely about four seconds. Going back to the opaque state took a lot less time at less than half a second.

To apply the graphene layer to the paper, the researchers first had to vaporize the graphene on a layer of nickel in an oven. Then the metal is removed by etching. After removing the metal substrate, a graphene film remains on the water. Then the paper is dipped in the water with the graphene film, which is then left behind on the paper. As a final step, the paper is dried at a temperature of 70°C.

Multi-pixel display made of paper and graphene. Source: ACS Photonics

To get a change in the light transmittance of the graphene, the paper must be covered with graphene on both sides. The graphene functions as an electrode at the top and bottom. In order to possibly make figures in the graphene, care must be taken to remove a strip of graphene, so that it is no longer connected to the adjacent surface. By providing or not supplying power to different tracks at the top and bottom, it is possible to control pixels individually.

The next step that the researchers want to take is to make electronic paper that consists of small pixels and an integrated circuit to control them. It may be possible to get batteries with graphene electrodes on the paper substrate, says lead researcher Coşkun Kocabaş in Nature Photonics.