Efficient Blue-Light-Emitting Polymer Heterostructure Devices: The Fabrication of Multilayer Structures from Orthogonal Solvents

An all-solution processed organic light-emitting diode with enhanced device efficiency based on an additional methanol-soluble polyfluorene layer (see figure) with nonionic ethylene glycol side chains is presented. Due to an asymmetric shift of the energy levels at the polymer/polymer interface, significant efficiency enhancements were obtained.