One-dimensional micro-scale patterned conjugated polymer structures in bilayer architecture and light emitting diode application

Abstract To maximize luminescent brightness in organic light-emitting diode (OLED) systems, charge transport dynamics of emissive layer is needed to be controlled. Herein, we pattern aligned micrometer scale conjugated polymer structures using a solution based processing method. Super yellow (SY)-polyethylene oxide (PEO) nanofibers were electrospun using simple uniaxial electrospinning method. A hybrid bilayer of SY-PEO fiber and poly (9,9-dioctylfluorene) derivative PFO film was formed by the sequential deposition of the electrospun fiber and spin-coated film. The maximum brightness of hybrid LED devices was increased over 1.7 fold to that of film-film bilayer device possessing same average film thickness. Besides, optical properties such as absorption/luminescence of SY were modulated by the rapid crystallization and solvent evaporation during electrospinning process compared to the spin-coated film. The electroluminescence enhancement and color control was attributed to balanced charge transport and enhanced Forster resonance energy transfer (FRET).