A Thermal Transfer Approach for the Doping of Organic LEDs

摘要

An effective process of performing controllable doping of polymer films in organic light-emitting devices is reported. In this approach, a film to be doped is brought into direct contact with a dye-dispersed polymer donor film to permit direct dye-diffusion thermal transfer. Theoretical and experimental studies indicate that this doping process can be modeled by Fick's diffusion theory and that a desired dopant distribution from shallow to flat profiles may be obtained in a single transfer step by adjusting the diffusion conditions. Doped-polymer light-emitting devices made by this process and the conventional blending process exhibited same device characteristics. Along with patterned color donor plates, we demonstrated multicolor OLEDs of arbitrary patterns over large areas with a single thermal transfer step.