Fabrication and properties of self-assembled films of poly(thiophene) derivatives

We fabricated electrostatic self-assembled thin films with poly(thiophene-3-acetic acid) (PTAA) as a polyanion and a positively-charged second-order NLO chromophore as a cation. UV-Vis, FT-IR, and second-harmonic generation (SHG) were measuredin orderto investigate the process of anion and cation adsorption andto understand the relationship between structure and optical properties of the ultra thin films. UV-Vis and FT-IR spectra of these films indicated that PTAA and the NLO chromophore formed a layer-by-layer structure. SHG measurements suggested that the NLO chromophores were noncentrosymmetrically aligned within the self-assembled films.