Chiral poly(fluorene-alt-benzothiadiazole) (PFBT) and nanocomposites with gold nanoparticles: Plasmonically and structurally enhanced chirality

Materials with large chiral optical activity at visible wavelengths are of great interest in photonics, particularly as a route to chiral optical metamaterials. Here, we demonstrate the plasmonic enhancement of the chiral optical activity of chiral poly(fluorene-alt-benzothiadiazole) (PFBT) doped with gold nanoparticles. The supramolecular helical organization of polymeric chains with simultaneous dipole-dipole interaction of the helically ordered nanoparticles with the polymer and one another results in unprecedented values of chirality parameter (κ ∼0.02) at visible wavelengths in thin films.