Maskless RGB color patterning of vacuum-deposited small molecule OLED displays by diffusion of luminescent dopant molecules

A maskless RGB color patterning technique based on diffusion of luminescent dopant molecules is proposed here for vacuum-deposited small molecule OLED displays. The proposed maskless color patterning technique enables us to overcome challenging issues in OLED display manufacturing arising from shadow mask limitations. This approach utilizes selective diffusion of luminescent dopant molecules from a donor substrate to an acceptor substrate. Results show that sufficiently high doping levels can be achieved through this technique and that devices with performance similar to those produced by standard co-deposition can be easily produced. Red, green and blue OLEDs are successfully fabricated side by side on one substrate using this technique.