Highly-efficient broadband waveguide outcoupling in light-emitting diodes with self-organized polymer blends

Abstract

Self-organized, two-dimensional micron-scale photonic structures fabricated within the emissive layer of polymer blend light-emitting diodes (LED) were discussed. The relief-and-phase grating was shown to be achieved by phase separation of two semiconducting polymers directed by a surface chemical pattern. It was observed that by introducing the appropriate texture into polymer blend thin films using a surface-directed self-organization, the quantum and power efficiencies of polymer light-emitting diode (LED) is doubled. It was found that the increased efficiency is due to harvesting of the waveguide photons.