High performance ITO-free white organic light-emitting diodes using highly conductive PEDOT:PSS transparent electrodes

We report high performance white organic light-emitting diodes (OLEDs) based on high conductivity poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films optimized by a solvent post treatment. The device stack is carefully optimized with high efficiency tandem structures including red, yellow/green, and blue emissive materials. The OLED with the PEDOT:PSS transparent electrode achieves a high power efficiency of 26.1 lm/W and an external quantum efficiency of 19.3%, which are comparable to the reference indium tin oxide (ITO)-based OLEDs. In addition, it is observed that the angular emission characteristic of PEDOT:PSS-based OLEDs is closer to Lambertian distribution compared to that of the ITO-based OLED. We show that the optimized device stack together with post-treated PEDOT:PSS transparent electrodes can realize high performance ITO-free white OLEDs.