A conducting polymer of diphenyldithieno[3,2-b;2′,3′-d]thiophene (DPhDTT) was synthesized via potentiodynamic method in dichloromethane (DCM)/acetonitrile (AN) (1:9 (v/v))–NaClO4/LiClO4 (0.1:0.1M) solvent–electrolyte couple. Characterizations of the resulting homopolymer were performed by cyclic voltammetry (CV), Fourier transform infrared (FTIR) and UV–Vis spectroscopy. Moreover, the spectroelectrochemical and electrochromic properties of the homopolymer films were investigated. Consequently, P(DPhDTT)/PEDOT device was constructed and their characteristics were examined in detail. A potential range of 0.0–2.0V was found to be suitable for operating the P(DPhDTT)/PEDOT device between yellow and blue colors. The device reveals good open circuit memory and stability.