The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology (FEP) together with partners, has succeeded for the first time in producing OLED electrodes from graphene. The electrodes have an area of 2 × 1 cm2.
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.
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 degrees. 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.
Figure: Fraunhofer FEP Orange luminous OLED on a graphene electrode
Dr. Beatrice Beyer, FEP's project leader, said, "This was a real breakthrough in research and integration of extremely demanding materials." Beatrice added, "The first products could already be launched in two to three years."
Graphene is considered a new miracle material. The advantages of the carbon compound are impressive: graphene is light, transparent and extremely hard and has more tensile strength than steel. Moreover, it is flexible and extremely conductive for heat or electricity. Graphene consists of a single layer of carbon atoms which are assembled in a kind of honeycomb pattern. It is only 0.3 nanometers thick, which is about one hundred thousandth of a human hair.
Due to their flexibility, the graphene electrodes are ideal for touch screens. They do not break when the device drops to the ground. Instead of glass, one would use a transparent polymer film. Many other applications are also conceivable: in windows, the transparent graphene could regulate the light transmission or serve as an electrode in polarization filters. Graphene can also be used in photovoltaics, high-tech textiles and even in medicine.
Source: Fraunhofer FEP / Gladiator