Fujifilm and nanoelectronics research institute imec have demonstrated full colour OLEDs created using a jointly developed photoresist technology. The partners say this approach – which enables sub micron patterning – paves the way to producing high-resolution and large organic electroluminescent (EL) displays and establishing cost competitive manufacturing methods.
Red, green and blue organic EL materials were patterned, each in the subpixel pitch of 20µm, to create an array of 40 x 40 dots with a resolution of 640pixel/in. Illumination with ultraviolet light confirmed that red, green and blue dots emitted light separately.
According to the partners, organic EL displays are increasingly used in televisions, mobile devices and wearables. Resolutions of at least 200pixel/in are needed for 4K televisions, while full HD mobile devices require 500pixel/in displays.
Fujifilm and imec say the results could open new applications, including creating an OLED array that adds a fourth colour to red, green and blue, as well as developing sensors that integrate an OLED with an organic photodetector.
Pic: The left hand image was taken with UV illumination on the OLED array, confirming that red, green and blue dots emit light separately. The right hand image was taken with voltage applied.