| Orgatronics, or organic electronics is one of the fields in science that enjoy increasing interest. As possible applications for organic devices increase, so do the number of publications and patents, and the financial support by governments and the private sector around the world. Compared with semiconductor electronics, organics have several advantages: tunability, flexibility, low cost fabrication, large area fabrication, smaller ecological footprint (in terms of energy consumption and waste production during fabrication and use). One of the challenges, but also a big potential, of organic devices is aggregation and patterning. Organics can take one or more of the following aggregation states: liquid, amorphous solid, single crystalline, polycrystalline, nanocrystalline, liquid crystalline. Electronic and optical properties may vary significantly, depending on the aggregation state. Here we report on the control of the molecular aggregation state by mesoscopic patterning. The micronsized patterns can consist of droplets, lines, and networks and are formed by casting from solution. Self-organization processes, such as dewetting, take place during solvent evporation that lead to the above mentioned patterns. After a general introduction to non-equilibrium states and dissipative structures, the presentation will focus on the preparation and photophysical characterization of the following kinds of organic samples: 1. Micronsize aggregates of cyanine dyes 2. Organic light emitting diodes consisting of micronsized amorphous hole transport material 3. Organic light emitting diodes consisting of aggregated micronszie hole transport material 4. Controlled microcrystallization of aromatic organics 5. Large aspect ratio fibers of charge transfer complexes and combinatorial chemistry of electron donor and acceptors 6. Organic field effect transistor made of crystalline fibers of an electron acceptor 7. Mesoporous polymer films for applications as photocatalysts and in dye sensitized solar cells. |
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