A novel electroactive star‐shaped rod‐coil copolymer composed of a benzene core and three symmetrically positioned tetraaniline‐b‐poly(ethylene glycol) arms, (TAni‐b‐PEG)3 rod‐coil block copolymer, is synthesized successfully and characterized using Fourier transform infrared spectroscopy (FTIR), UV–vis, 1H NMR, and matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry. Uniform and high‐quality (TAni‐b‐PEG)3 thin films onto indium tin oxide‐coated glass surface are fabricated simply from its DMF solution. Resulting (TAni‐b‐PEG)3 copolymer thin films possess excellent electrochromic properties with a high optical contrast of 73.3%, superb coloration efficiency of 318.5 cm2 C−1 at 750 nm. Very short switching times, that is, 2.11 s and 2.14 s for coloring and bleaching times, respectively, are observed as well. The mechanism of these impressive electrochromic properties of (TAni‐b‐PEG)3 thin films possessed is proposed based on the atomic force microscopy investigation, star‐shaped molecular geometry, synergetic electronic and ionic conductivity and amphiphilic self‐assembly feature of (TAni‐b‐PEG)3 copolymer, which can self‐assemble to form cylinder pattern consisting of quick pathways for electronic charges and ionic species, respectively.
