We demonstrate high-efficiency small-molecule-based white phosphorescent organic light emitting diodes (PHOLEDs) by single-active-layer solution-based processes with the current efficiency of 17.3 cdA-1 and maximum luminous efficiency of 8.86 lmW-1 at a current density of 1 mA cm-2. The small-molecule based emitting layers are codoped with blue and orange phosphorescent dyes. We show that the presence of CsF/Al at cathodes not only improves electron transport in oxadiazole-containing electron transport layers (ETLs), but also facilitates electron injection through the reacted oxadiazole moiety to reduce interface resistance, which results in the enhancement of current efficiency. By selecting oxadiazole-based materials as ETLs with proper electron injection layer (EIL)/cathode structures, the brightness and efficiency of white PHOLEDs are significantly improved.
All Science Journal Classification (ASJC) codes
- Materials Science(all)