Organic electronics plays an increasingly important role in modern technology and society. A variety of electronic gadgets based on organic material have already entered the market. However, there is general agreement that still much effort is necessary to improve the properties of such electronic devices. For this purpose a deeper understanding of the fundamental processes underlying organic film growth is required, because it is known that the electronic properties are mainly determined by the structure and morphology of the organic films. The proposed project will investigate the very initial steps of organic film growth, i.e. adsorption, diffusion, nucleation, coalescence and beginning multilayer formation. It is known that these initial steps are largely responsible for the properties of the final organic film. The investigations will be performed under well controlled, ultrahigh vacuum conditions. A large number of surface analytical techniques will be applied to characterize the substrates and ultra-thin organic layers. In particular, thermal desorption spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy will be used, in addition to other common surface analytical techniques. Within this project also several national and international co-operations will take place and there will also be an intensive collaboration with theory groups. The main issue of this project is to tailor the film growth by special preparation procedures and by proper structural and chemical modifications of the substrates. Nano-structuring of the substrate by grazing incidence ion sputtering and molecule deposition under grazing incidence are just two proposed ways to tackle this issue. Two different groups of organic molecules will be used for the investigations, which are either important test molecules and/or relevant for technical applications: Rod like molecules (quaterphenyl, hexaphenyl, pentacene) and plate like molecules (hexaazatriphenylene hexacarbonitrile, copper-phthalocyanine). As substrates mica, silicon oxide and single crystal surfaces of gold, silver and copper will be used. All these substrate and film materials are relevant for applications. The final goal of this project will be to develop a comprehensive model for the nucleation of organic molecules, which is a prerequisite to tailor organic thin film growth. We strongly believe that the outcome of these investigations will not only be of academic interest, but also of considerable importance for the organic electronic industry.
|Effective start/end date||1/06/11 → 31/05/15|