Synthesis of polypyrrole-coated core/shell nanoparticles

The synthesis, physical characterization and scale-up of conductive, re-dispersible core/shell nanoparticles containing polypyrrole (PPy) in the shell are described. The compressed powders/films show a DC conductivity which is considerably higher than that of commercial standard products based on PEDOT/PSS ('AL 4083' from H.C. Starck). The particles have excellent film-forming properties since thin films (50-100 nm) made by spin-coating from aqueous dispersions of the particles have an AFM film roughness of <15 nm even before annealing. The materials were tested as hole injection/smoothening layers in fluorescent OLED devices, and are in a comparable range to PEDOT/PSS-based materials in respect to performance (film forming, luminance, efficiency, and lifetime).