Technology of conductive polymer PEDOT:PSS films

The structural, optical, and electrical properties of copolymer poly(3, 4-ethylenedioxythiophene):(styrenesulfonic acid) (PEDOT:PSS) thin films deposited from aqueous solution have been investigated. To increase the conductivity three different dopants have been used: dimethyl sulfoxide (DMSO), sorbitol, and ethylene glycol. Even though the dopants increase the conductivity by three orders, the surface morphology and optical properties do not change significantly. The discussion on secondary doping effect is carried out to explain the observations.