title: Study on the disparate transition behaviors of the electrical/physical properties in PEDOT:PSS film depending on solvent species under a follow-up solution-treatment process.
abstract: In most solution-processed organic devices, a poly(3,4-ethylenedioxythiophene) (PEDOT) polymerized with poly(4-styrenesulfonate) (PSS) film is inevitably affected by various conditions during the subsequent solution-coating processes. To investigate the effects of direct solvent exposure on the properties of PEDOT polymerized with PSS (PEDOT:PSS) films, photoemission spectroscopy-based analytical methods were used before and after solvent-coating processes. Our results clearly indicate that
  PSS films undergo a different transition mechanism depending on the solubility of the solvent in water. The water-miscible solvents induce the solvation of hydrophilic PSS chains. As a result, this process allows the solvent to diffuse into the
  PSS film, and a conformational change between PEDOT and PSS occurs. On the other hand, the water-immiscible organic solvents cause the partial adsorption of solvent molecules at the PE surface, which leads to changes in the surface properties, including work function. Based on our finding, we demonstrate that the energy-level alignments at the organic semiconductor/electrode interface for the
  PSS films can be controlled by simple solvent treatments.
authors.affiliation: Analytical Science Laboratory of Samsung Advanced Institute of Technology, Maetan 3-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803, Korea.
authors.forename: Dong-Jin
authors.initials: DJ
authors.lastname: Yun
authors.forename: Jung-Hwa
authors.initials: JH
authors.lastname: Kim
authors.forename: Seong Heon
authors.initials: SH
authors.lastname: Kim
authors.forename: Minsu
authors.initials: M
authors.lastname: Seol
authors.forename: DaEun
authors.initials: D
authors.lastname: Yu
authors.forename: Hyukju
authors.initials: H
authors.lastname: Kwon
authors.forename: Yongnam
authors.initials: Y
authors.lastname: Ham
authors.forename: JaeGwan
authors.initials: J
authors.lastname: Chung
authors.forename: Yongsu
authors.initials: Y
authors.lastname: Kim
authors.forename: Sung
authors.initials: S
authors.lastname: Heo