Electrochromic Insight on Electro-Deposited Copolymers of Push-Pull Conjugated Systems with 3,4-Ethylenedioxythiophene (EDOT) and Other Conjugated Units

Abstract

Third generation conducting polymers (CP) are push-pull type conjugated systems, which include both electron pushing and pulling units in their chemical structure. Push-pull design enables coarse and fine tuning in the electro-optical properties of the resulting CP such as lowering the band gap and enhancing electrochromic properties. Push-pull CPs have been widely used for various applications such as electrochromic devices, displays, light emitting diodes, organic solar cells, field effect transistors, electrochemical and optical sensors etc. This review aims to collect electrochemically synthesized CPs of push-pull systems in the literature, up to 2023. Most of the studies include 3,4-ethylenedioxythiophene (EDOT) as co-monomers, but there are also other studies such as obtaining push-pull type CPs by copolymerization, and copolymerization of push-pull systems with other units. Each case is discussed in separate sections. In the scope of this review, only electrochemical copolymerization studies are selected, and the effect of monomer feed ratio and the polymerization conditions on the electrochromic properties of the resulting copolymers are discussed and summarized in tables. This collection can serve as a guide for upcoming copolymerization studies, by giving an insight into optical and electrochromic properties of various copolymers of push-pull systems so far.