A conducting polymer of 3,5-diphenyl-2.6-dithiophene-2-yl-dithieno[3.2-b;2'3'-dithiophene (Thy(2)Ph(2)DTT was synthesized by potentiodynamic method in dichloromethane (DCM)/acetonitrile (AN) (1/1)-NaClO4/LiClO4 (0.1:0.1 M) solvent-electrolyte mixture. The resulting polymer was characterized via cyclic voltammetry (CV). Fourier transform infrared (FOR) and UV-Vis spectroscopy. Its dual type electrochromic device (ECD) with PEDOT was constructed. Spectroelectrochemical and electrochromic properties of the polymer film and the device were investigated in detail. A potential range of 0.0-2.0 V was found to be suitable for operating the P(Thy(2)Ph(2)DTT)/PEDOT device between red and blue colors. The device displayed good open circuit memory and stability. Properties of Thy(2)Ph(2)DTT and P(Thy(2)Ph(2)DTT) were compared with 3,5-diphenyldithieno[3,2-b;2',3'-d]thiophene (Ph2DTT) and its polymer P(Ph2DTT), reported previously, which revealed that introduction of thiophenes to the peripherals of Ph2DTT improved the properties of the corresponding polymer. (C) 2012 Elsevier B.V. All rights reserved.