| dc.description.abstract | The interface between electronic and biological systems and the ability to interconvert biological and electronical signals, that can be provided using an organic electrochemical transistor (OECT), can greatly affect our lives for the better. The possibility of direct detection of ions, metabolites or signalling molecules can ensure both better prevention and more effective treatment of many diseases. Synthesis and characterization of novel materials for OECTs is the primary focus of this thesis. In three research chapters, the basic design and gradual alternation of structures of novel polymers with gradual improvement of OECT performance and stability are discussed. The fifth chapter is devoted to the expansion of the currently small group of small molecules suitable for OECT applications. The second chapter of this thesis deals with the synthesis and characterization of new polymer materials with a high concentration of glycol side chains, suitable for OECT applications. The structures of the materials were chosen so that it was possible to investigate the influence of the electron density of the conjugated backbone on the overall performance. The design of the materials is based on materials with a central tetrafluorophenylene unit previously prepared by our group, the best representative of which showed figure of merit µC* = 10 F·cm−1·V−1·s−1. The new design brought a series of novel polymers, the best of which showed figure of merit µC* = 69 F·cm−1·V−1·s−1. The third chapter deals with further derivatization of the materials prepared in chapter two. Thanks to the newly developed synthetic strategy, both new materials and regioisomers of the materials from chapter two were prepared. Mentioned materials were optically and electrochemically characterized, and it was found that almost identical regioisomers can show up to a sixfold difference in the figure of merit, which was for the best material µC* = 268 F·cm−1·V−1·s−1, which was at the time a new record among glycolated polymers. The fourth chapter deals with the synthesis of building blocks suitable for better arrangement of polymer side chains in the solid phase. It also deals with the derivatization of the best performing polymers from the previous chapter. To improve their stability, derivatives with fluoride substitution, with a methylene linker between the conjugated backbone and the side chain, and subsequently a derivative combining both structural changes were prepared. Fluoride substitution of the best performing material from the previous chapter brought an increase in its OECT operational stability from t1/2 = 342 s to t1/2 = 2620 s. The fifth chapter deals with the synthesis of new small molecules, which are structurally based on the only known p-type small molecule that was able to function as an OECT. By changing the central units and introducing additional donor substituents, a new series of molecules with a gradually increasing HOMO level was prepared, which was tested in OECT applications. | en_US |
