Producing functional OLED electrodes from graphene
03 January 2017
Fraunhofer researchers and partners from industry have succeeded, for the first time, in producing OLED electrodes from graphene.
Graphene presents many advantages: graphene is light, transparent, durable and has more tensile strength than steel. Moreover, it is flexible and extremely conductive for heat or electricity. It is only 0.3 nanometres thick and has a variety of applications – for example, as a touchscreen in smartphones.
The electrodes developed by Fraunhofer and partners have an area of 2 x 1cm2. The production of the OLED electrodes takes place in a vacuum. In a steel chamber, a wafer plate of high-purity copper is heated to about 800°. The research team then supplies a mixture of methane and hydrogen and initiates a chemical reaction. The methane dissolves in the copper and forms carbon atoms, which spread on the surface. This process only takes a few minutes. After a cooling phase, a carrier polymer is placed on the graphene and the copper plate is etched away.
"This was a real breakthrough in research and integration of extremely demanding materials," says FEP’s project leader Dr. Beatrice Beyer. The process was developed and optimised in the EU-funded project "Gladiator" (Graphene Layers: Production, Characterisation and Integration) together with partners from industry and research.
Beyer says the first products could be launched in two or three years’ time. Due to its flexibility, the graphene electrodes are ideal for touchscreens and if the device is dropped, it won’t break. Other applications include for windows, the transparency could regulate the light transmission or serve as an electrode in polarisation filters. Graphene could also be used in PV’s, high-tech textiles and medicine.
The project was launched in November 2013 and the Fraunhofer team is working on the next phase until its conclusion in April 2017.