High-Performance Hybrid White Organic Light-Emitting Devices without Interlayer between Fluorescent and Phosphorescent Emissive Regions

摘要

White organic light-emitting devices (WOLEDs) can be used as solid-state lighting sources, backlights for liquid crystal displays (LCDs), and full color OLEDs. Recently, hybrid WOLEDs have drawn considerable attention due to their unique advantages of combining the blue fluorophores excellent stability and the high efficiency of long wavelength phosphors. In general, hybrid WOLEDs can be constructed using two architectures, including multi-emissive-layers (multi-EML), or a single-emissive-layer (single-EML), with different color emitting dopants. The concentrations of the phosphors in the single-EML hybrid WOELDs need to be precisely controlled in order to realize the desired color since a small variation in the dopant concentration would result in a pronounced change in the energy transfer between the emitting dopants. Besides, the notorious spectra variations associated with different applied voltages represent another drawback.