Development of OLED displays using graphene transparent electrodes
19-inch monitor level, electrode thickness of 5 nanometers or less

ETRI (Electronics and Telecommunications Research Institute) succeeded in developing a display by creating electrodes using graphene, known as the "dream material," instead of indium tin oxide (ITO), which was widely used as an electrode for existing OLED displays.

The display substrate successfully developed by the research team measures 370mm x 470mm, which is the size of a 19-inch monitor. The thickness of the graphene electrode is less than 5 nanometers (nm).

ETRI anticipates that combining graphene with a flexible substrate will enable the realization of thin and flexible displays. If this happens, it could become a source technology utilized in the production of wearable devices applied to clothing or skin.

Generally, OLEDs are stacked with a substrate, an ITO transparent electrode, a light-emitting organic layer, and an aluminum layer serving as the anode. The research team replaced the commonly used ITO with graphene.


ITO materials, which were previously used as electrodes, have glass-like properties, posing a problem of breakage even when fabricated into displays and utilized as transparent electrodes. In contrast, graphene possesses flexibility, which can solve this issue.

This research was conducted jointly with Hanwha Techwin. We have developed a technology for growing graphene on a large-area substrate and a transfer technology for application as OLED transparent electrodes, and have secured processing and manufacturing technologies for graphene transparent electrodes applicable to OLEDs, having a sheet resistance of 60 Ω/m² and a transmittance of over 85%. In particular, we have developed the first micro-patterning process, which is indispensable in display manufacturing.

ETRI utilized this technology to successfully light up a 370mm x 470mm panel, the world's largest graphene electrode OLED panel.

In the future, we plan to develop displays using plastic substrates instead of glass substrates. When flexible graphene is combined with a plastic substrate, it is possible to fabricate wearable OLED devices.

"We attach great significance to the fact that we have realized the general expectation that graphene can be applied to OLED displays for the first time. We anticipate future commercialization through large-area graphene film and OLED panel technologies, as well as flexible OLED panel technology," said Cho Nam-sung, Head of the Flexible Devices Research Group at ETRI.