Films of organic polymers were prepared and investigated as insulating layers in contact with phthalocyanines as organic semiconductors for use in organic field effect transistors. The polymer films were obtained either by a high-vacuum technique based on the thermal decomposition of polymers and polymerization of the fragments on a substrate, by the spin-coating of polymer solutions or by the cross-linking of spin-coated precursors. Poly(vinylchloride), poly(vinylidenefluoride), poly(acrylonitrile), poly(methylmethacrylate), poly( N -vinylpyrrolidone), poly(styrene), poly(4-vinylpyridine), poly( N -vinylcarbazole) and a polyimide were used as polymers. The film growth was studied by mass spectrometry and infrared spectroscopy. Electrochemical measurements by cyclic voltammetry served to analyze the properties of the polymer films. The morphology was determined by atomic force microscopy. Interactions of the films with phthalocyaninatozinc ( PcZn ) was analyzed for co-evaporated PcZn in the polymer films, to probe the chemical compatibility of the methods. Subsequently, evaporated PcZn or hexadecafluorophthalocyaninato-oxo-vanadium ( F 16 PcVO ) thin films were studied in detail by UV-vis spectroscopy and by electrical measurements to investigate interface formation, intermolecular coupling and electrical conduction in such films. The applicability of the different polymers as dielectric layers in organic field effect transistors, with phthalocyanines as the active semiconductor thin films, is discussed, based on their dielectric behavior and observed growth characteristics.
Air-stable n-channel organic field-effect transistors based on charge-transfer complexes including dimethoxybenzothienobenzothiophene and tetracyanoquinodimethane derivatives
