New generation materials have aroused great interest over the last decades due to their potential applicability in the next generation electronics such as electrochromic devices(ECDs), solar cells, light emitting diodes and biosensors. Conjugated polymers (CPs) are good candidates for a variety of technological applications. ECDs belong to one of the most popular and widely studied fields and CPs as nest generation materials are mostly used in this field due to promising behaviors.

Poly(3,4-ethylenedioxythiophene) (PEDOT) is one fo the most popular polythiophene-derivative conjugated polymers and widely used in the research for copolymerization due to its fascinating properties such as low band gap at around 1.6 eV, high stability, good conductivity and so on. Given these certain advantages, many reports have indicated that EDOT is a good candidate for a variety of electrochromic studies.Another interesting and fascinating group is azobenzene with its desired properties such as bright color, good stability, low flammability, and reversible photoisomerization

In recent study, novel electrochromic copolymers of 3,4-ethylenedioxythiophene (EDOT) and (E)-1,2-bis(2-fluoro-4-(4-hexylthiophen-2-yl)phenyl)diazene (M1) with different monomer feed ratios were designed and synthesized electrochemically.(E)-1,2-bis(2-fluoro-4- (4-hexylthiophen-2-yl)phenyl)diazene) (M1) and EDOT comprising novel copolymers CoP1.5, CoP1.10, and CoP1.15 with the different monomer feed ratios (M1:EDOT equal to 1:5, 1:10, and 1:15) were designed respectively.Copolymerization of the azobenzene-bearing monomer with EDOT unit improved the electrochemical and electrochromic behaviors significantly. The resulting copolymers showed very low oxidation potentials at around 0.3 V, multichormic behaviors with red shifted adsorption, and lower optical band gap values compraed to those of P1.

As a result of the promising electrochromic and kinetic preperties, CoP1.5-bearing single layer electrochromic device that works between purple and light greenish blue colors was constructed and characterized. Finally, CoP1.5 was used for ECD construction, and the single layered device was characterized in terms of electrochemical and spectroelectrochemical features. Resulting ECD worked between –2.5 and +2.5 V and exhibited purple and light greenish blue colors at the two extreme states (neutral and oxidized) with 12% optical contrast.