Organic LEDs could create cheap, flexible displays

Work by researchers at Seoul National University could lead to the production of cheap, high-quality displays and sensors through the use of organic LEDS. While these LEDs cannot at the moment match the brightness and efficiency of non-organic LEDs, the researchers are confident they can progress the technology through integration with non-organic semiconductors to a point where it will be able to compete.

A team led by Gyu-Chul Yi, a professor of physics, found that they could create bendable LEDs by growing gallium nitride rods that are only micrometers in height on graphene. The LEDS glow bright blue and retain their brightness, the researchers found, after being flexed 1,000 times.

The professor outlined his findings in the online journal APL Materials.

He said that he expects that the discovery to lead to the creation of cheap displays and sensors, as well as touch panels and smart contact lenses. Flexible LEDs have been created in similar ways in the past but Yi explained that, through the method of using highly crystalline gallium nitride micro-rods grown on high-quality graphene – his team’s LEDs boast better brightness, flexibility and strength.

The under layer of graphene is essential to grow the micro-rods that are vertically aligned so that the resulting LEDS offer colour-tunable light emission and a high integration density. There is no suggestion as to when this type of technology could come into wide scale production as yet, but Yi and his team are working to hone higher-quality LEDs by optimising the metal contact layers and adjusting the micro-rods’ size, position and density.