Preparation of PEDOT layers

Layers of in -PEDOT are deposited by mixing EDOT, an oxidant, e.g. Fe(III) tosylate, and optionally imidazole first [52, 89, 90]. The butanolic solution is spin-coated on to a substrate where EIX)T polymerizes to doped PEDOT while drying. The remaining oxidant is removed by purging the films in deionized water followed by a second drying sequence. Several successive processing steps are needed to obtain finished Alms. 

To obtain uniform films from aqueous dispersions of PEDOT PSS, the solution has to be filtered carefully to remove dissolved particles, e.g. dust or small amounts of aggregated PEDOT PSS. For small quantities, a syringe equipped with a PVDE filter of pore-size 0.45 tim or less is sufficient for most applications. The solution is then deposited on a thoroughly cleaned substrate (cleaned by using common techniques such as plasma cleaning, UV ozonizing or wet cleaning). Clean, fat-fl ee surfaces are imperative for proper PEDOTiPSS deposition. 

PEDOTiPSS dispersions can be deposited by multiple techniques including spin coating, doctor blading, dip coating or ink jetting. Spin coating is regarded as the most reliable technique to obtain uniform thin layers. 

Although the PEDOT PSS complex is a prefabricated polymer, in contrast to the in -PEDOT films, its film properties are heavily influenced and therefore can be adjusted by formulation - the addition of film-forming binders, surfactants, wetting agents, adhesion promoters, etc. 

Common formulation components and their effects on PEDOT PSS films are as follows  

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