It is well known that the implementation of flexible organic electronic devices (FEDs) in our everyday life improve and revolutionize several aspects of our behavior. Although there has been considerable progress in the area of flexible inorganic devices (based on Si), there are numerous advances in the organic (semiconducting, conducting and insulating), inorganic and hybrid (organic-inorganic) materials that exhibit customized properties and stability, and in the synthesis and preparation methods, which are characterized by a significant amount of multidisciplinary efforts. The understanding of the organic material properties can lead to the fast progress of the functionality and performance of flexible organic electronic devices. An crucial ingredient for this is the strong interdisciplinary nature of the area of organic electronics, which brings together experts in chemistry, physics, and engineering, removing the traditional boundaries between the individual disciplines. Therefore, the understanding of the properties of organic insulators, semiconductors, and conductors as well as the effect of their synthesis process, microstructure and morphology is the goal of the current research efforts. In this work, we summarize on the latest advances in the fields of organic (semi-) conducting materials and hybrid barrier layers to be used as active layers and for the encapsulation of the materials components for the production of FEDs (such as flexible organic light-emitting diodes, and organic solar cells).