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 N LO chromophore as a cation. UV-Vis, FT-IR, and second-harmonic generation ( SHG) were measured in order to investigate the process of anion and carion adsorption and to understand the relationship between structure and optical properties of the ultra thin films. UV-Vis and FT-IR spectra of these film s indicated that PTAA and the NLO chromophore formed a layer-by-layer struc ture. SHG measurements suggested that the NLO chromophores were non-centros ymmetrically aligned within the self-assembled films.