Star-shaped conjugated systems derived from thienyl-derivatized poly(triphenylamine)s as active materials for electrochromic devices

A star-shaped molecule, tris[4-(2-thienyl)phenyl]amine, which contains triphenylamine as core and thiophene as arms, was successfully synthesized via Suzuki coupling reaction. Poly(tris[4-(2-thienyl)phenyl]amine) (PTTPA) was electrochemically synthesized and characterized. The resulting polymer film exhibited four various colors under different potentials. Moreover, the PTTPA film showed high optical contrast (38% at 430 nm, 29% at 560 nm, and 53% at 710 nm) and satisfactory response time (2.57 s at 430 nm, 0.76 s at 560 nm, and 2.10 s at 710 nm). An electrochromic device (ECD) based on PTTPA and poly(3,4-ethylenedioxythiophene) (PEDOT) was also constructed and characterized. This ECD was found to have good switching times, reasonable contrast, and satisfactory optical memories and redox stability.

This figure shows spectroelectrochemical spectra of the tris[4-(2-thienyl)phenyl]amine film on ITO electrode as applied potentials between 0 V and 1.2 V, and the images of polymer film under various potentials..Figure optionsDownload as PowerPoint slideHighlights
► A star-shaped molecule tris[4-(2-thienyl)phenyl]amine (TTPA) was synthesized.
► Its polymer films were synthesized via electropolymerization and characterized.
► They presented distinct color changes with good switching time and optical contrast.
► An electrochromic device based on the polymer and PEDOT was constructed.
► The device displayed quick switching time and reasonable stability.