Poly(3,4-ethylenedioxythiophene)

For example, the polymer is optically transparent in its conducting state and has high stability, moderate band gap, and low redox potential.

[2][3] Its major disadvantage is its poor solubility, which is partly circumvented by use of composite materials such as PEDOT:PSS and PEDOT-TMA.

The idealized conversion using peroxydisulfate is shown: Polymerization is usually conducted in the presence of polystyrene sulfonate (PSS), which acts as a template.

PSS also provides a counter ion, which balances the charges in the reaction and hinders the formation of by-products such as 3,4-ethylenedioxy-2(5H)-thiophenone, and keeps the PEDOT monomers dispersed in water or aqueous solutions.

[4] The resulting PEDOT:PSS composite can be deposited on a conductive support such as platinum, gold, glassy carbon, and indium tin oxide.