Processing and Characterization of Organic Thin Films

This work deals with two of the major challenges in organic electronics: (i) the optimization of organic/inorganic contacts through interface engineering and (ii) the prevention of intermixing in multilayer solution-processed devices. (i) A suitable method to control organic/inorganic interfaces, not only in terms of interface energetics but also to control the morphology of subsequent layers is the use of self-assembled monolayers (SAMs). Various SAMs from commercially available precursor molecules have been investigated in detail with the aim to optimize the processing parameters for high-throughput fabrication. On the basis of the gained knowledge and experience SAMs composed of novel molecules with strong dipole moments were investigated. (ii) The second part of this work addresses the problem of intermixing of solution-processed thin films. To this end, the film formation was studied of n-type semiconductor materials based on 1,4,5,8-naphthalenetetracarboxdiimide (NDI) with additional thermally cleavable side groups that govern the solubility of the molecules. Both polymer and small molecule organic semiconductors were studied.