Enhancement of white light OLED efficiency by combining both internal and external light extraction structures

摘要

We proposed an internal nanostructure with a high reflective index planarization layer to solve the optical loss due to thereflective index mismatch between ITO and glass substrate. In our experiments, we found the electrical property ofOLED device was significantly influenced by the internal nanostructures without planarization layer. Moreover, theinternal extraction structure (IES) is not necessarily beneficial for light extraction. Therefore, we proposed a newsubstrate combine both internal and external extraction structure (EES) to extract trapping light. We successfullydeveloped a high refractive index (N~1.7) planarization material with flat surface (RMS roughness & 2 nm), andimproved about 70% device efficiency compared to traditional glass substrate.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.