Although there are some advantages of PEDOT:PSS films, including high conductivity, high transparency to visible light, excellent water solubility, and being environmentally-friendly, PEDOT:PSS solutions are acidic owing to the PSS polymer with a –SO3H group donating the hydrogen ions. This results in the etching of the ITO surface as the PEDOT:PSS films are deposited on the ITO substrates using a spin coating process, which is attributed to the migration of indium and tin into the PEDOT:PSS film. In this paper, a PEDOT:PSS solution was treated with ammonia with different volume ratios prior to deposition. It is found that ammonia treatments can totally neutralize the hydrogen ions and reduce the AIn3+/AIn3+(pristine) atomic area ratio of PEDOT:PSS surface calculated from the XPS data due to the inhibition of the degradation at the PEDOT:PSS/ITO layer interface. Furthermore, the ASO3H/ASO3− on the PEDOT:PSS surface obviously changes with ammonia-treated solution at pH < 7, and APEDOT/APSS is greatly influenced by an ammonia-treated solution at pH > 7, which affects the surface energy of PEDOT:PSS film, helps improve the film roughness, and enhances the electrical conductivity of the films.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry