At the moment there are efforts to replace the classical transparent conducting coating, Indium Tin Oxide, (or other TCO's) by a new class of materials, which are easier to handle and cheaper in mass production. Possible choices are transparent conductive coatings, which consist of polymers. In this investigation PEDOT:PSS is used. Carbon nanotubes are added in order to render the film electrically conductive. A prerequisite for its use is long-term stability. Therefore the degradation of PEDOT: PSS/ carbon nanotubes as a function of time is determined.